Ohk enough with the "glittering" cannons, the "lightsabres", the "star wars" effect. If you would make a really realistic mobile suit with existing weaponry of today, now that wouldn't be so boring eh?

Example, MObile suits doesn't have thrusters, yet. They have propellers, like Murasame models.

Instead of beam swords, stick with the electric sword, maybe like GOUFS.

NO MORE rail cannons, beam rifles, and posistron cannons, launcher packs. Instead, we go with pure metal ammos, nails and tacks..hahaha, bullets of course.

I would use Strike's structure, equip it with gatling gun, electric sword, and magnet gun. The paint job would probably suck, so no more phase shift armours!, just put ur name on it, damn it I dont care. The power source would probably be fuel...or worse charcoal..hehe. Anyway the point is, the lower you dream, the better.