((Oh, good! If there's anything unclear/missing, please mention it so that someone can fix it. The wiki is perpetually a work in progress, so feedback is always nice.
1: As far as optimizing, make charisma and speech zeros. I can count the number of times either stat has been rolled in this whole game, on one hand. It's entirely possible to completely avoid using either of those, without losing any functionality except in very specific circumstances.
2: Next, I suggest you go with Exotic weapons instead of Unconventional. As far as space magic, Exo is entirely better; the only advantage of uncon is that you can also use advanced melee weapons like kinetic amps and monofilament blades. If you do this, drop Intelligence to zero as well; the only uses for int are qualifying for manips, and having your character think for you.
Those are the basic suggestions that cost basically nothing. Here's more risky/costly stuff.
3: If you buy a sub-exoskeleton model C, for two tokens, you get +3 to strength and endurance rolls. That's six points to spend elsewhere. Further, it allows you to use AUX rolls to control your exoskeleton like a puppet, meaning you can use aux in place of dex and strength for stuff like dodging and melee combat. It's possible that it can even let you circumvent the CON penalty of a fleshtech by using AUX for shooting conventional weapons.
The problems with that are that those require specialty programs to be written. You could get them from my char, Steve Saint, but his programs haven't been tested, and he's dead at the moment.
There's probably more that I forgot, but I'm tired. Sorry.))
1: If he plans on using the flesh/mindwarping amps, high charisma is a must. That is charisma's only use.
Speech has been rolled way more than 5 times. That's why there's the joke about speech rolls always being failed or overshot. That joke would never have been made if there were no speech rolls. For example, Charles sometimes uses speech to mind control people.
2: That is not the only advantage to uncon. You can have an unlimited number of manipulators, but only 3 amps. realistically, 2 amps and a decomp. There is a universal manip, but no universal amp. Kinetic shunts uses uncon. So do grenades. Amps leave the user temporarily disabled after too much usage, manipulators don't. Manips can be used as emergency nukes. Piecewise always keeps track of mind points, but he rarely keeps track of ammo.
3: Sub-exoskeletons provide a +1/3, not a +3 strength and endurance. That won't make up for a -1 to the stat. You still can't use it to shoot guns with aux, that requires an auxiliary weapon hardpoint.
Also, roleplaying. Some people choose their stats to match the character, not to be the most powerful. I don't enjoy roleplaying a character with 0 intelligence, but who somehow acts intelligently. Or a character with 0 charisma who somehow acts charismatic.