Whoever installed this opener they actually took their time of what the hell they were doing they did everything correctly that I see so whoever installed it I give them an A+ for it
The idea of an opener on the basement door could be possible. If mounted on the right side, there is a bit of room for the rail bracket to go, and as far as the door arm goes, you could do the thing that nick did with one of the two 8550s and make a metal square for the J arm on the door to connect to the straight arm on the right side. But your choice.
Yknow I gotta say, the one thing I hate about my genie belt drive unit is that it's not smooth at all, it's decently quiet but the door jerks quite a lot