Many sites in the same VPS
Hi, I'm completely new on VPS. I have hosted more than 30 sites in a shared hosting over the last 10 years, and I think it is time to start using a VPS.
I'm not a developer, and I don't know about Linux or creating servers. Because of that I'm proud of me after creating a droplet, installing VestaCP, adding domains, etc, and now I see my test sites on line. Anyway, I have a few questions, that I hope you can help me:
1) Is it safe to host many sites in the same VPS, under the same IP? I mean: if one of my sites has any problem (let's say, it is in a google's blacklist), the rest of my sites will have any problem?
2) Is it recomendable to host the most important sites in an individual VPS to avoid any kind of problem? Or is this a stupid thought?
3) Is it possible to host regular sites (like html or php) within Wordpress sites in the same droplet?
4) Last: how can I calculate the size of the droplet I need? I was looking at loadimact, but I don't understand how to transform all that data into the answer about which droplet specifications I need.
Many thanks for your help in advance, and sorry for my ignorance!