I would reduce to 25%. Don't go too thin- the paint needs body.
I roll out with a 3/16" roller. The roller has to be well rolled out in the pan to get the paint load down. The amount put on boat is still about 6 square feet. I roll and tip by myself. I tip vertically. I have two brushes ready and throw out the first as I pass the stem. Don't try to cover in one coat. You will need to sand out for the second coat (one of the pains as apposed to spray). It takes some time to find the correct brush- needs to be a very fine bristle and not so heavy as a badger type varnish brush. Sand out your bad coats till you have no brush marks left- 220 and a quick pass with 320 is fine for this.
The key with roll and tip work is to lay down a good paint film with the roller. Roll out the roller in the pan to get the paint load down. Roll on the paint in the area you KNOW you can cover well with the paint on roller (~6'). Back roll once to settle paint film and tip right away. It takes some time to learn to do right
The tip brush needs a light touch- too deep of an angle or to rough and you will cut furrows in the paint film which can not settle (same is true for too course of a brush or a brush which is not fresh or too wet). You need to move fast. I roll and tip a forty foot sailboat of low freeboard in less than an hour. It takes some time to get up to speed but awlgrip is a very good product for brush work on large surfaces like hulls. The work can equal or surpass most spray jobs if you nail it. Personally I now spray everything but did a number of hulls roll and tip before I got around to buying the gear for spray.
The just tipped paint should look like a sheet of water on the hull. If you see brush marks it has too little paint or bad brush/brush work. Too much paint and the runs start. Good ideal to look over your shoulder to catch runs before they 'set'.
Just use acetone to clean up.
Don't use foam anything.
Paint at 77 degrees w/humidity less than 45%
Just found this roll/tip link in another thread: http://www.boatbuildercentral.com/he...g_roll_tip.htm