I don’t know what Trump thinks about abortion, and neither do you. (I do agree with the position he expressed at one point that there should be legal punishment for women who have abortions, though he walked it back). I do know for a fact however that Clinton is terrible on abortion, so there’s that.
I think government involvement in health care (and most other sectors of the economy) should be massively expanded, too.
The main reason Trump is a Republican is that a lot of Republicans voted for him in the Primary. That’s all it takes. If he didn’t appeal to Republicans, they had plenty of other options to vote for.