It's a common quandary Nick, this business of signing or not signing a print. Limited Edition prints may have some merit in direct-to-mat signings, but I'm not convinced enough to do it. I sign on the back or on the Certificate of Authenticity that accompanies each print, framed or just matted.
Individuals will develop their own style and preferences relating to framing over time. Generally experimentation will take place (often in consultation with a dedicated framer), errors will be made and days will come and go when you seriously wonder if you're doing the right thing. By you, yes you are, but don't be afraid to change your spots. Years ago I made some spectacular errors in framing, choosing gaudy double-mats for the (then) RA4 prints under dull glass. All that work was so utterly bad, so utterly disappointing for all the cost and effort, so utterly unfulfilling that it went into the incinerator on a Total Fire Ban day. My mood didn't get any better.
Signatures are very often terrible on any art medium and many photographers do reflect and rue the "defacement"; signing direct to the surface of an Ilfochrome is sacrilege — it's on a par with shooting Bambi. I scanned one and only one signature about 14-15 years ago (of my full name) that still goes on all my prints as rear titles. Ever the Artful Dodger, there are of course others: 6 other signatures, 3 different names (nom-de-plums), heaps of forum names, 2 genders and several unusual qualifications additional to Photography. Your guess is as good as mine who you're dealing with tonight, honey, LOL!!!