It's good to see people attempting this. It can be fun or frustrating, so I think it's always better to play considerably over-rolled rather than under-rolled. Coming from a poker background, I think it's really easy to underestimate the variance of blackjack (as the variance in poker is so much lower and the winrate is so much higher compared to blackjack).
There's no way the casino doesn't know who you are and what you're doing at the green/black chip level. If I were to guess, they probably have you flagged as a counter by now. However since you're playing rated (there's nooooo way they'll tolerate this action if you play unrated within a short time frame IMO), they choose to tolerate it for now. They probably want to see if you're a potential whale or an ap.
Don't take my word for it... These are just my educated guess. Every casino and condition is different, and I'm not exactly too sure what yours is. Listen to what the veteran posters have to say and take their words over mine, although my guess is they'll probably say the same thing (btw, which forum is this?
I think 50% pen (60% is ok) sucks for a DD relatively speaking. However I've never heard of a DD game with surrender (there's probably only a few offered in the country assuming you're from the us) and since late surrender is offered (which is ridiculously good), I don't think there's a need to increase your bet size unless conditions tell you otherwise and that you can get away with it. I just ran your game below using hi-opt2 with asc and noticed that the SCORE for your game is 108. That's pretty damn good...
I also remember a poster by the name of KJ or Ke.wlJ,ason (listen to him if he's there) recommending not to make a bet over $500 since that apparently rings the second level of threshold for a typical casino ($100 being the first).
The graph I first posted means within 4000 hands (I didn't realize that wasn't shown), you're expected to win 9k or lose 3k within 68% of the time. If you've played poker before, you should know what that means theoretically and understand it's effects in practice. I'm assuming 4000 hands since 50 hours * 80 hands/hour is 4000.
Here's an updated graph at 25 to 2x 300.