All powerglides have the removable input shaft, but with it having 30 splines that means that it is to be used with the T350/T400 torque convertors and that it is an aftermarket and stronger shaft. It does sound like you do have a manual valve body kit in it. The other item that it should have with those mods would be a steel hub inside the front clutch drum instead of the cast steel that is stock. The 1.76 planetaries are the stronger ones from stock.
Your question "does any of this sound good?" really depends on how much you paid and are expecting out of the transmission, but those are the basic upgrades to make it live. Other items that could have added would be a Kevlar band or a dual ring servo piston, but I doubt that it has those mods.
Your next question "is there anything to look at to tell if its good or bad?" do you mean physically bad? That would be clutch material in the pan or burnt fluid. Or chipped teeth in the planetaries. If it has set for a lot of years, the seals could be getting hard, so a basic rebuild could be in order with new clutches and seals.
Bill M