Powerfists?
So far, spikes and blades seem to be weaker on boots than on armor, across the board.
As for them being separate, that's generally fine (though I'd like a "Bodycheck" feat, then), it's just that heavy armor doesn't go well with melee at all;
For an unarmed character, you need high dex, either agility (speed) or will (range) and if you want to wear heavy armor, better dump that agility, because you also need 8 strength minimum and some constitution as you sure as hell won't evade anything.
Also, for actual good armor, you need a modicum of int, it's rare to find a decent one in the shop; Last (my first full) playthrough, I haven't seen any tungsten armor, regen or galvanic vest components, good helmets, decent knives, or armor with a good amount of spikes or blades, in any vendor at all.
It might be a lot more viable if you could put spikes on leather armor, or get aluminium and titanium alloys.
On armor that heavy, you suffer from MAD, so the only proper weapon seems to be an actual weapon; And why not pick a sledgehammer if you have 8+ strength anyways?
I'd suggest an "Armor Training" feat that reduces the adverse effects of item encumbrance, say, capped at 80%, f.Ex.
Also, energy shields might fix the entire issue due to allowing you to be slow
and short ranged and still have a fighting chance.