Moon: She loves video games, so give her specific types to focus on, such as RPGs and/or Strategy games like Fire Emblem. You could also have her become interested in Tabletop RPGs somehow (such as one of her parents having played them in colledge and Usagi getting ahold of old (or new) source books they kept.
What about First Person Shooters? Since Sunny seems to have abandoned Gunslinger Moon, I don't think he'd mind if I hijacked his concept and put my own spin on it...
Jupiter: She was already the "Martial Artist" of the group, boost her Dan levels and add Ki use and Kino Makoto will be ready to kick some ass.
Wouldn't have it any other way.
Venus: Best options I can think of are either a love for militaritic fiction, or liking mahou shoujo manga making her gleefully genre savvy.
Oh lord... I don't know what made me think of this all of a sudden, but I'm stricken by a sudden mental image of Sailor V wearing a pair of orange v-shaped sunglasses instead of her traditional mask...
Uranus: She alreay likes motorcycles, add in Mechanic skills so she can "personalize them" (read: make them faster and add other things to them regardless of common sense) and andrenaline junkie traits......
Here too, I'm getting images of Uranus pulling a Fate/Zero, and jousting with a youma on her motorcycle with the Space Sword in one hand.
Saturn: The manga had her father using mechanical parts to save her after the accident, but only doing so halfassedly. Up that to full fledged Hollywood Cyborg, with Mercury providing upgrades once she joins the team.
Pluto: Drop the "Time Gates let her know everything" trait and let her do intelligence gathering by other means, whether it's just scrying, or more traditional methods.
Detective Pluto and Combat Cyborg Saturn? I'm getting jitters just thinking about it. But what's Tux boy going to be getting up to while the others are busy becoming Made of Awesome?
Even magical archery like Kagome would make here extreme range fighter in anime canon, detection and protection with charms all over Tokyo "Silent Mobius" style is good idea too... And i even don't want to go in Shinmei-Ryuu...
I think Mars will probably have a lot of binding spells and pyromancy more than swordsmanship, but it's definitely worth thinking about.
Actually with analytical branch of "Mizuno Enterprises", they computerized scanning equipment everywhere, one boy prophet and magical scanning net parallel to computerized electronic one... Senshi will be in place of Yoma incursions before Yoma would knew that they are starting incursion there and i mean literally so. And being at place of yoma attack not because of luck, but because of prep will change badass level greatly i'd say...
The youma are also going to be taking a few levels in badass, if only so that the Senshi don't curbstomp them every time they show up. I'm thinking the Generals will probably have the manga's power levels and the youma will attack in large groups after the first few battles.
Also, which boy are you referring to?
I dunno if I could contribute much, but I've always thought that a bit more... 'destructive' spells would have made the series better. What you need is to give the Senshi some SRW-esque finishers, the likes of which Apotheosized Ialdabaoth and its pilot, Folka, would be proud of.
The spells we have are already plenty destructive, you just don't see the results of the attack as often as you do in, say, Nanoha. If I actually wind up writing this thing, one of the main things I'm going to focus on is a lot of descriptive text and generous helpings of collateral damage; streets melting under Mar's fire, windows blowing out whenever Jupiter smashes some poor guy into a building, etc etc. Though the idea of Saturn turning the Silence Glaive into a BFS and screaming about being The Sword that Cleaves Evil is
intensely amusing.
Rifts deliciously comes to mind.
I'm completely unfamiliar with Rifts. Can we make her Genre Savvy instead from watching too much anime?
Finally, make her more serious about being a magical girl, possibly due to excitement over the whole Sailor V thing and becoming a serious fan before she becomes Sailor Moon.
That's pretty much a given. I'm definitely keeping Moon on as the heavy artillery, but I also want to give her some lesser attacks so she won't be useless until the girls set up the kill for her. Turning her into Asuna On Steroids seems like a fun way to do that. Maybe I can have her take interest in martial arts--not intensely so, like Makoto or Haruka, but casually, as a way to stay in shape?
Venus- I agree on the M-16 thing, get her involved in something bigger. I'd also recommend having her recover her crystal sword, making the crescent beam more destructive, or at least having a 2nd stage version of it, and making the chains more like those used in some of the Nanoha binding attacks by Arf, Yuuno, and Chrono, and possibly like a whip sword type thing as well with bladed links if used a certain way.
I like the idea of Venus being a secret agent, but I think the crystal sword might get passed up on just because it's on the moon and Venus has no way to get there. On the other hand, I fully intend to expand on Venus's metal alignment more than her energy powers; Unlimited Blade Works, anybody?
Mercury- so much can be done here, but I'd like to specifically reccomend some things based on Naruto characters. Her early mist trick for hiding can be combined with a sort of silent killing thing, sneaking up on the enemy and using a deadly physical attack in close combat with her senshi enhanced strength in a surprise attack to a vital point.
Twin ice daggers are a must for this.
Have her do something like snap some youma's head off or stick her arm through their chest in a trust from behind while the fog is up.
Seems kinda...
violent for Ami. Taking advantage of the fog is a very good idea as a combat tactic, though.
I'm not so sure about the doctor or adventurer archeologist character archetypes, as they don't seem to really fit Ami that much, instead, I'd go more the Lina Inverse type route, she learns so much about the subtle details of magical theory and does so much research that it enhances her techniques and spells beyond the normal levels and she can figure out unconventional counters to the opponent's techniques on the fly.
I actually think Mercury would be better as a Hermione Granger-type spellcaster; less powerful than the others, but her high IQ and above-average grasp of her powers makes her much more flexible than the others are with numerous spells they wouldn't be able to pull off.
And now for my personal favorite senshi, Saturn. While being able to level a few city blocks sounds cool the REAL potential of her ability's is that she can destroy ANYTHING... Like say, the connective tissue holding her enemies together, or for even more overkill, the atomic bonds in their bodies for a nice atomic boom. Of course this would be a STRICTLY off planet move but still...
You're not thinking on a small enough scale. Deconstruct their genetic data and turn them into piles of dust. Or invert the Silence Wall and turn it into a projectile attack, Getsuga Tenshou style.
PS. Hotaru cutting M9 from herself using EoDP is very badass i think btw.
Nah, Saturn doesn't need Death Perception to be a badass. Just give her some skills with the Glaive and set her loose. Halberds and polearms are intensely badass if properly used, and if this is Hollywood Cyborg Hotaru we're talking about, then we can have all kinds of other goodies built into her as well.