How is the Shared MySQL server (VPS)

I am planning to start a new blog + forums soon on a VPS from Dreamhost and was wondering about the quality of the shared MySQL server that comes with the VPS.

I would also like to ask if there is any limitations on the VPS offered by Dreamhost, like a maximum number of processes or something similar (assuming I have not consumed the allocated resources of course)

Also is NGINX still offered for VPS users? That’s one more reason I decided to come here and join DreamHost to be honest.

What about CloudFlare, and Railgun? I know they are both offered totally free for Shared users, is it the same for VPS?

And last but not least do you think a VPS from Dreamhost will suite my needs? I am planning to start a gaming blog in my native language using WordPress, along with forums based on vBulletin 5 (without CMS or Blogs and no add-ons too). Will the VPS be able to handle this, fast? And if I run out of RAM, I heard I can add more using the control panel but I am not really able to find the prices for RAM only at all.

Sorry for asking a lot of questions but I just wanted to make sure that whatever I am going to start with, keeps with me forever or almost forever. I don’t like changing hosts, or moving from shared to VPS every now and then.