I think you've got a Northern Cardinal in there. Definitely a lot of familiar sounds, but him only doing them for a bit at a time makes it harder to place them. I'm not sure if those are car alarms, or a particularly loud rendition of an alarm-like bird, but I think he's got a "your car is now unlocked" beep in there.
Mockingbirds choose mates based on who has the most impressive mimicry repertoire, not based on plumage. I'm not sure what they find attractive, but I'd imagine this one's got a good shot- lots of variety!
There are Blue Jays in my neighborhood that can manage some shockingly good Red-shouldered Hawk calls. I've heard the local mockingbird trying to do an American Crow caw, but he can't get it nearly as deep and rasping as it needs to be, so he sounds cartoonish instead.