I have transformed all of them back and forth several times. They have good design in whhich when you are about to accidentally add too much pressure, the ball joint disconects - Similar to some official toys.
In regards to tabs on Sonic Drill, I have not had any issues. They just need to be aligned and are stubby enough not to feel they are going to break.
Yeah the light cycle was a really cool choice for alt mode. That's what I like about Maketoys/FansProjects and also MMC - They don't just try to mimic G1 but provide their own takes on the characters. That is also why I liked Classics and subsequent lines too.