Yeah, well those are all part of the campaign system... you play a series of games and as your models gain experience they gain new abilities which are represented by those upgrades. They also gain injuries, like broken arm. The Leader one is probably available if your Henchman leader dies mid-campaign, though I haven't read up on specifics of how the campaign works yet.
Basically, they have not been balanced for typical play. Most people play a 50ss game because that's where the game is balanced. You could ask your opponent if they mind you using one or more of those campaign only upgrades, but it'd probably be on a case-by-case basis.
Keep in mind there's different types of upgrades in there, Equipment which generally has a cost is easy enough to add with your opponent's permission, but Skills generally have a cost of 0 but represent a campaign model after it's lived through enough encounters to gain the skill. I'd recommend either staying away from Skills outside of campaign play, or determine a cost.
Honestly, if you like the upgrades I'd say start a campaign. It's what they were designed for.