I will have to do some research on your printer because I'm not familiar with it, but here is a rule of thumb. the smaller the layer ht the less exposure, 15 is high for.03, your bottom layers look ok but the bottom exposure seems way high,your cooking it to the FEP and not the build plate, try more around 80, looks to me like you are over exposing.
Here are setting i use on my AnyCubic and i use Phrozon ABS like resin Grey.
Layer height-.05 (you don't see much difference between .025 and .05)
Exposure - 12 or 13 ( rule is to start at .05 and add 25% exposure if you go to say .10 and minus 25% when you go down to .025, so if i went to .025 my exposure would be roughly 2.5 - 12 =9.5, you can work on fine tuning those for your printer) note: If you use a clear resin(any color) you can lower your exposure even more because the light pass's though the resin better. when you start printing things with little holes you will see what i mean,to much exposure and the resin in the holes will get cured also and the result is no hole.
Bottom layer count 6-8
Bottom exposure 80 - 100
I don't have a heater installed but i live in Florida so no big deal, but 75 degrees +/- is ok, you can always let the bottle sit in some warm water also before you shake it to print...Remember to always shake!!!!
Orientation- yes at an angle, you want to have the least amount of material trying to peel from the FEP, you don't have to go full vertical, 45 degrees is a good starting point and yes it may have to print all day.
Another tip: after you have cleaned your tray after a print you can use a micro fiber towel to make it clear again because it does fog up from the resin and alcohol after each use.
You may have to do some searching but there should be plenty of info on the web for your unit.
If you need anything else let me know.
Almost forgot, looking at your sliced file you could use some more supports on the corners, don't be afraid to add more then you need until you get more familiar with your printer.