Help me understand difficulty of ownership

I would say it depends on what you buy. If its all stock or OEM upgraded parts have been used then its pretty simple. If the car is highly modified with aftermarket parts then things can get a bit complicated because you don't know what they used, the condition its in, or how they may have wired it.

The good news is you found a site with a lot of knowable folks, so ask away. It will be the easiest way to gain knowledge on what your doing.