Here's a short video (and picture) of my brand new rebuilt 235 running at idle. Running 40 PSI.
The motor hasn't run more than 20 minutes at the time of this video.
https://photos.app.goo.gl/GhbcuqTLEzsXeD0i1
The kind of oil is entirely up to you as there as many opinions on that topic as pebbles on the beach. Just use a good one, with a good filter and change it often.
I've read often times also that 5 psi at idle is quite normal and nothing to be concerned about.
Your water temp should be close to 195 to get proper power. They like to run hot.