Installing the tap at an angle will have very little to do with damaging the washer inside (at least in the short term here) so I don't think that is an issue here.
Lining the tap up properly, well, in most cases, if you increase the number of wraps of teflon tape on the threads of the tap then you shouldn't have to tighten the tap quite as much and you should be able to line up the tap vertically as needed.
Finally, if your bib tap is leaking after only a year of use I am going to figure that the tap is very old or the seat is damaged and tearing up the washers very quickly. In this case, I would simply recommend that you replace the entire bib tap and that really should resolve all the issues you presented.
Last edited by plumber2011; 06-25-2011 at 02:27 PM.