zippered pockets, or not? inside pockets?

Yes zippers on the outside pockets and there are deep inside pockets but they are not zippered

I am 5’7” tall I weigh 205 lbs (waist 37-38); should I get a size medium, large or an extra large? Thank you.

I would recommend an extra large. Husband is 5'11" and has a 38" waist and the extra large fits him fine. He normally wears a large, so I would say this runs a bit small.

How small is this when packed away?

Super small, like the size of can of beer but soft of course. Be careful; the one I purchased had a rip at the hem and the sellers hasn’t corrected the issue.

I bought a vest before that was 2x but it was too small will 2x plus give the extra space i need or should i get a 3x plus?

2x plus will only give you more length but not more room girth wise. If you need more room in the girth area but don’t need the additional plus/length, then just go to 3x size. Otherwise go to 3x plus