Hi Tim I don't think it is such a big deal screwing filters, after all I and others have been doing it for years without any mishaps
In your light polluted back yard you could build a surround, out of say tarp or hessian or some other material to cut down the light intruding on your space.
Filters are no good for galaxies, UHC would be the best filter to use, I often use it in moonlight to some good effect.
Don't let your location spoil your interest in the hobbie, try to use your imagination to make the situation better
I know of people who observe from the middle of Chicago and do some reasonable work.
When you then go out to a dark sky site you will appreciate your efforts more
Last but not least go to an observing night with other observers and get some first hand advice.
