1. They don't have any ground huggers like the Ultari in GH2. The only wheeled vehicle I know of is the Tauner, it's a ground car with a turret. Well, technically also the chameleon - but it's just a battroid with wheels on the legs.
2. If you want to load a mech with lots of armor and weapons, find something thats light (so you get less mass penalties to MV/TR just from the body) and has a large engine (bigger engine = larger carried weight before you start getting penalties). If you can get your hands on one, a Dao Deoji is an amazing mecha in this regard. It has a huge class 8 high performance engine, and most of its parts have significantly reduced weight. I got a real nice one as salvage after fighting a Blades of Crihna patrol. The high performance increases your MV/TR by +1/+1, at the cost of a 1/2 battery for energy weapons - but you could always strap on some low weight batteries (which you can pull off a variety of sources - ovaknights have a bunch of 0.5t class 2 batteries in the legs, and the lowly starwarrior buruburu carries a 2t class 4 and 0.5t class 1s) to get plenty of power. A regular class 8 engine produces 5k power, the high performance one makes 2500 - a class 4 battery makes 2500, so one class 4 battery that weighs 2t offsets the disadvantage of the +1/+1 bonus that lets you carry at least 7.5t (even more if you're carrying the stuff externally).
3. Not sure about cyber docs, I haven't really did much with implants in GH2 yet.
4. You need a computer to install the computer program. There are personal scale programs and mecha scale programs - the mecha scale ones are the ones that take up really high numbers of ZeGs (computers are rated in that, thats how much space it takes on the computer). You can buy computers, but the stock ones are really heavy - you can pick up light ones off mechs. The Crown comes with a 1.5t class 5 and the Vadel has a 0.5t class 2. The software from stores goes up to +3, but you can get a +5 TR and a +4 tracking bonus (that helps against fast moving bots) from some of the higher end designs (Kraken or Chimentero, for instance).
5. To get loadout readings you need a target analyzer software. Trailblazers come with light class 1 computers preinstalled with that.
6. I don't think you can reorganize it without removing and replacing the parts, but you can't remove the torso so if you replace the head you're stuck with a torso above the head. You could edit the save file to move it I guess.
7. I believe the blasts are X tiles out from the center, so a blast 1 is a 3x3 and a blast 3 is a 7x7.
8. Polymath is nice. All of the situational bonus to mecha combat ones like Hull down or Born to Fly or whatever are good on asteroids and inside spinners, but in most cases you'll be fighting in space where none of them apply. Not entirely useless, but the usefulness is limited. Hard as Nails is a great way to improve your survivability in personal scale. Acrobatics is also nice if you have dodge skill, since it gives you double the chances to not get hit at all. It restricts you do tier 2 armor, but wearing a cheap tier 2 armor with a cheap weapon is a great way to get experience - and anything really lethal you're probably better off dodging than hoping for the heavier armor to save you anyway. Stunt driver is real nice because it applies any time you're going full speed, and honestly going full speed is a bit OP in GH already - if you're moving fast enough the enemy gets a huge penalty to hit you, while you only get a -3 to hit him, and with the talent on top of that you also get two dodge rolls.