[@KoL]I always thought that the suit was just super advanced tech that didn't violate any physics laws.  Basically, it just used tech that was 100 years more advanced than current tech.  Sometimes he would use materials that don't exist here (like the stuff Thor's hammer is made of, or adamantium), but it was mostly supertech.
For example, I'm going to have Tyr recognize the suit's synthetic fuel as a crystalline material in his world that is used as a neutron sink and fusion catalyst for proton chain fusion (fusion which uses the lightest isotope of hydrogen).  It's not used by people in his time because fusion power is inferior to the anti-matter power they normally use, but it's not unheard of on lower tech worlds.
Also, the suit has built in heat sink/radiators for the reactor, to keep him from being burnt by it.  The thrusters in his back and feet even use [url=https://en.wikipedia.org/wiki/Thermal_rocket]thermal propulsion[/url] to shed heat.

Besides, the tech wouldn't work in this world if it required different rules and those changes didn't come through.