Oh god. Where to start.
1. Strength enhancement - Well, you seem to have the right idea with the bending polymers, now you just have to find a way to tell your suit to send a charge through it when you want it to. That alone would probably cost loads.
2. Motion sensors - I'd go with what the other guy said, having a kid's "spy" thing, except mount the sensor somewhere on your suit.
3. Invisibility - Is not feasible at this time. Sorry. Scientists have yet to invent a metamaterial that can bend all wavelengths of visible light, and a system using cameras and screens would cost way too much and wouldn't hold up under any kind of combat condition.
4. Overshield - Definitely not feasible. I've spent many nights awake wondering how to make an energy shield... they were all way too expensive or wouldn't work.
5. Healing unit - If you seriously need one of these in a suit you're using for paintball, then that's some crazy-ass paintball you're playing.
Also, some of my own ideas and questions.
6. Visor - Instead of a see-through polycarbonate (or whatever you use) visor, just make it molded with the rest of the helmet, install a screen on the inside of it, and mount a tiny camera on one of the holes on the side of the helmet where the LEDs usually go. That way, you can put in a HUD also with your ah, "shield" level, plus the motion sensor.
7. Power - Even if you manage to get all this stuff... how're you going to power it? Fusion power on the scale of the reactors in the actual Halo canon (Backpack sized reactors) is about as far off than energy shields. Batteries would run out damned quick, and solar panels would only be able to be mounted on limited parts of the armor (unless you plan to wire up your whole undersuit or use a seperate battery pack for each invidvidual piece of armor you need it in) and would probably ruin the look of it, not to mention they would shatter under paintball conditions. Beaming power with microwaves like they did at Reach wouldn't work either, that technology is in its infancy (just like invisibility/light-bending metamaterials). A gas-powered or diesel-powered generator would be heavy, hot as hell, and probably too big to fit anywhere on your suit, not to mention the carbon monoxide fumes it would emit.
We can always dream. :-D