So did a quick look around, on the building and modifying constructs page, under the construct modifications header, it says a construct must be inanimate or nonfunctioning to be modified, so you won't be able to work on yourself sadly :(
I unless...you were to use a simulacrum of yourself :D maybe buying them items to boost the relevant skills, that or find someone you trust, and is capable of performing the modification
As far as how many constructs you can control, that would be between you and the gm, giving an order is a free action (look at druids and animal companions)
While their is no hard limit to how many free actions you can take, the gm is free to cut you off when he feels like it, however, your being a mental link, he hopefully won't limit you to what you could say in a 6 second span, more what you can think...maybe work out a mechanic with him, that lets you issue a number of orders based on intelligence, like 2 per modifier, or some such
That being said, you should be able to control your body while giving said orders.
Also golems do not have will, but that doesn't make them dumb, they will seek to perform your orders "to the best of their ability" so if you tell them to kill something, they should use the tools at their disposal to get the job done, this will be up to your gm (being NPCs, you give an order, then he controls the specific action)
But if your golem has a mega-death cannon arm of Doom, he will use it, unless perhaps he also has a mega-death sword of doom- and the target is in melee range.
Same goes for special abilities, if you tell a mithril golem to chase someone down, and they lock themselves in a room, it won't bother breaking down the door, it will just use it's ability to turn liquid, and slip underneath.
Goloms can do a lot without constant orders too, a simple order like "protect me" and that golem will follow you around, and lash out at anyone who sells to do you harm, without any need for further orders
Or, if you know your in enemy...
any information is welcome :)
the arm cannon really depends on the DM being willing to let me take salvage from other constructs, the annihilator robots tail cannon would be AMAZING given it does 20d6 fire and elec damage in a line so i dont need to hit AC, Unicron just shoots (unicron being a HEAVILY MODIFIED quintessece golem
i did figure out a way to build a golem that my character can inhabit, costs 195000 gp, but its a medium mithral golem, so....its interesting to say the least
backstory for the character is that his biggest and best creation Unicron accidentally stepped on his body and killed it, the mithral golem just kinda standing there looked like a good body to use given his original is paste now
if the DM doesnt lilke it, 16500 for another mind link, and i keep the android body
and with an int score of 24(+4 from a certain book) Beep is very smart and mentally capable