1: Yes. Your PSU does not directly power your monitors so you are fine running as many as you like.
2: You have plenty of RAM to run multiple monitors, and again, that is mostly up to your graphics card, which has ample resources for the task as well.
2.5: The RAM in most systems is only a small portion of the load the PSU sees. If a RAM upgrade is going to bump you over your PSU limit, you're already too close to it.
thanks for the fast and simple reply!