I've been drinking through a straw for 11 months now, so pretty much right after getting this. I got some metal straws as well the other day, but it's kind of hard to drink with them, compared to plastic ones that can be pressed together by the lips. But I'll try using them more to get away from plastic..
For me, it's not hard at all to keep the lips from getting wet in the shower. Just don't put your face in the water stream :-) If you have/want to, wash your face with a wash cloth in front of a mirror.
Same goes for brushing teeth: I don't get (well, except for some accidents) any water or tooth paste on the lips while brushing my teeth (I'm using an electric toothbrush).
I don't let any food touch my lips (and it's been working like that for 11 months; I haven't eaten things like burgers or spaghetti; and have pretty much changed my diet to a almost completely organic one, with waaay less meat, much more fruit and vegetables, and now I'm trying to eat less dairy as well; I'm not vegan yet but I have more and more vegan meals/days).
Talking is a problem for me.. it's pretty uncomfortable a lot of the time.. but I try not to avoid it.
Oh, and I'm not really doing the moisture treatment just yet, at least not completely.. I do moisture them (and use Protopic during nights) a few times per day, but after about a week or so, I gently use water to wash off the skin that by that time is starting to become very noticable/thick. Because of the almost constant moisture, there isn't even much trauma at all, most of the skin falls off when gently letting water run over the lips. Then using qtips to get the rest of the skin of might be causing trauma. And the lips being unprotected afterwards is probably causing the most trauma.