Focus on speed first. Once you become a good lag putter the rest will fall into place. I tried a belly putter and while it made me better on shorter putts I totally could not lag putt like I usually do. It was an experiment that lasted about a month. At the end of it I was carrying two putters which is just looney tunes or something Phil would do.
I play a lot of matches with my son on the pristine 9 at LPGC. Small greens make your short game better on a real course.
Golf is a cruel game. After a scrambling 79 that was truly terrible I shot an easy 74 where even mis hits ended up on the green.
if You French Fry when you should Pizza you are going to have a bad time