Hi,
Congratulations! Hopefully your project will go well this year as well. I also have done similar work, and there are plenty of ways in which you can take this; really it's all up to you. True, there isn't a ton of variation; many of the overall mechanisms for generating fluorescence are somewhat understood. However, I feel like a lot of this hasn't been done particularly quantitatively, so a lot of it has not been optimized (one thing you could look in to).
The first thing that popped into my mind (and again, you don't have to do this, this i just an idea) involves the lacZ reporter gene. In case you aren't familiar, I'll kind of briefly go over the process (more detail here
http://www.bio.davidson.edu/courses/gen ... rters.html). When you transform a plasmid into a bacteria, you want to make sure that your gene of interest is in plasmid, so you can engineer the plasmid with a lacZ site and make a cut site for the gene of interest within that lacZ site. If you successfully insert the gene of interest into the plasmid, it will cut the lacZ gene in half and inactivate it. So, when the plasmid is transformed into the bacteria, some of the bacteria will have the cut lacZ gene (meaning a plasmid with your gene of interest) and some will have a full lacZ gene (a plasmid without your gene of interest). The ones with the lacZ gene will produce beta-galactosidase in the presence of lactose and will catalyze lactose and produce a blue colored colony, whereas the bacteria with the cut lacZ gene (with your gene of interest) will not produce beta-galactosidase and therefore will not cause the colony to be colored blue (it will remain white), allowing you to differentiate between which colonies do and do not have you gene of interest. Now, the process is not 100% accurate since you can get false positives and negatives. I don't believe that this has been very well quantified or optimized, so you do have options in that respect, perhaps trying to modify some initial conditions like length of insert, length of plasmid, strain of bacteria, etc.
Alternately, some of the things that you suggest would work just as well. Extra plasmids and genes would seem to slow growth, but maybe initial growth (or later growth too, who knows?) so you could make a sort of time map of colony counts and sizes (maybe total area?) over time while varying the amount of DNA transformed.
Antibiotic resistance could also be fun to play around with. Maybe you could test the growth rate of satellite colonies or the growth rate of antibiotic resistant versus antibiotic naive bacteria in a non-antibiotic media. All of these sounds really promising; if you have any future questions on a specific direction, be sure to let me know!
Cheers! Hope this helps,
Aaron Lin