亲 is also more like a verb where 吻 is more like a verb and a noun. We use 吻 for I gave you a kiss (吻), you will not say I gave you a 亲. You could also combine the two words together to make a verb like, 亲吻你的爱人.
I dont think there's not much a difference between 待会儿 and 等会儿. It is both used quite commonly depends on the region I believe .
The difference between 待 and 等 depends on the context, but in this context they both mean wait.