My own experience is that EAD is very troublesome. You need to renew it every year. Practically you need to start the renewal process after 8 months your current EAD is approved. If you new EAD is approved within 2 months, you only use your EAD for 10n months. You have to set your alarm oclock every 8 months. And you cannot forgot.
I would recommend you to use H1B. fengxiang's suggestion is very good. I don't think you fully understand her/him.
Basically, EAD is yours, you will have it anytime you want it if you 485 is pending. But H1B is not. You cannot have H1B anytime you want it.
You have worried too much about if 485 is rejected. The painful part is waiting for the long process. As long as you have better life within the time while you are waiting, you should go for it.