Maybe it's a real body, just telepathically link and then control, heh, real titties.

Silly men. You don't control titties. You simply pacify them for the time being.
Modular arm sounds annoying. Why would you want to store an entire arm in your backpack? Perhaps lots of expansion slots on the arm to put stuff into (guns, ammo, additional computer systems, etc), but not an entire arm.

but you would be a robot, so you don't need to worry about weight besides the limits of the body, so you could easily turn off any "pain" you would receive.
this is all assuming we have very advanced methods of powering the suit, better hydraulics/biomechanics, etc.

Fun fact. Your muscles are artificially limited by the brain so that they do not incur too much collateral damage on other tissues that are not as strong, and might tear under the stress.

this is the future man, the future!

yeah, but hey, sometimes those limits are broken. drugs. adrenaline rush. your kids about to be killed.

NOOOOOO TIMMY

but umm how would one break these limits, would you have to go rock lee style and release your eight inner gates of sealmon

Basically your brain has to release the locks, which as stated is in a state of extreme panic and base instinct reaction. Whatever makes your brain stop worrying about damaging your own body.

Nope. The body can just apply it with adrenaline. But don't expect the ability to fly or something - it's a significant increase, but not a magic potion.

exactly. one of my teachers actually held up his car, a full SUV, from one side to prevent it from crushing his children, who had crawled under it while it was on a jack that was about to let loose. but he was extremely sore.

so apparently now we need to constantly pump adrenaline into the brain to make this all work, which I'm pretty sure has a detrimental effect T_T

Why do we need to?
Also, if we're using replaceable parts that's perfectly fine. Adrenaline isn't for the brain.

but we need to turn off the limiters in the brain... don't we? whatever chemical.
i assume we would just take out a great deal of sensors, such as "if weight limit exceeds this, cancel out X amount of signals sent back to the brain"

You just cut out the signals, no limit breaking needed. Actually, does the brain really have that much that you could detrimentally increase the performance of? I don't think there's that much...

That's not quite how it works, guys.
Pain is a factor that is honestly not that hard to overcome, you do it all the time when exercising. Moreover, it would be a better solution to numb parts of the body to avoid crippling pain… like with painkillers.
Pumping adrenaline for too long will really hurt you.
Hell, using your body too long will too, this is not a long-term solution for strength.
Turn off the limiters, and you will begin to fall apart. Your body will run out of glucose, then go into shock, leaving you unconscious and broken.

Better to upgrade, not try to overclock. That's the problem with fleshies, as while we can do all kinds of stuff, that limits us from being great at any one thing.
Thus, modularization is really the obvious way to go.
Need incredible hulk-like strength? You would be better off with a bulked up powersuit like body, with no excess weight.
Mobility? Drop those heavy arms and plantigrade legs for wing-fins and digitigrade legs.
Durability? Build like a tank, with one solid body part and treads.

Having everything at once is obviously a problem, because you start needing to make way more compromises.
Not to mention that once you've finished the task that needed one sort of body, you can rearrange and do something else.
We've already got really fine prosthetic legs for walking, and separate models of legs for running, swimming, or even just socializing.
Someday soon we'll begin seeing the "disabled" re-enabled. There are already runners with prosthetics that could beat probably every one of us here.

but that's the thing with people. we always want it in one package. like the iphone.

but i would definitely settle for a speed model. I'm a runner, so it would feel natural to move fast.

Meh. With the right technology you can just make it feel natural.