To answer the weight question - yes with both on board in the front you'd be at (or just past) the forward end of the envelope in a stock Cozy. Some might disagree with this but I'd say it's more of a C of G issue than a limit. A heavier engine or other adjustment (like putting batteries in the back or lengthening the rear fuselage a couple of inches) to put the C of G back in range might raise your minimum solo weight - (ie I couldnt fly it solo at 160#) but otherwise wouldnt cause much of a problem. You might end up with slightly less useful load and slightly higher landing speed.
Marc Zeitlin has a weight and balance spreadsheet on his website that you might find useful. You could do what if scenarios with it to see what weight changes would be needed and what the impact would be on minimum and useful load limits, fuel load etc.