How decent is this

Hello- I've been a sng / tourny player all of my "poker life" (of about a year). I've been pretty successful at it and have always sucked horribly at cash games. However, I always like to find systems to reduce variance as much as possible and I've heard cash games do that to an extent... so anyway, I decided to grind the s**t out of cash games 3-tabling the .25 / .50 Fixed Limit HE 9 seater cash games.

I don't have poker tracker, but what I do have are the basics:
1580 hands
$45 profit
~60 fpp
136/177 @ BB
77/187 @ SB
151/1216 @ op
total = 23%
pots won at showdown = 81/144 (56%)
w/o showdown = 45

So my major question = is this decent? I'm asking because this is my first real cash game sesh in my life. I have nothing to compare this to.

And my second - and more crucial question - involves higher stakes. I feel that most money comes from loose donks.. right? Looking at players / flop and money / pot / blind levels makes donk/table ratio pretty easy to figure out. Looking at .02/.04 you see that >50% enter each hand (and looking @ tables people 4-bet on tptk all day long).. by the .25/.50 its about 37% see a hand. But then moving up in stakes and this number drops off dramatically. By the $1/2 the number is right where I'm at ~20% - if I move up is it even feasible to get the same kind of profit margins if the donk ratio is clearly smaller?
As a follow up, when do I move up if ever? I'm fairly comfortable with this cash game thing but I know how quick money can go in these things...