a) quite a number of forum members over the years have gotten lip biopsies.
just search for the relevant search terms in the search box here, and you'll be able to read their stories.
i don't recall reading that ANYbody's lip biopsy was actionable - by which I mean, that the results showed anything that could be corrected, by surgery or medicine. however, i didn't pay too much attention to people's stories of lip biopsies, because i know that it's not an option for me.
if you are considering getting a lip biopsy, read the few commentaries that explained that a scar was left on the lip, although nothing good came out of the biopsy - therefore, such a step might not be worth it.
also, read david from sweden's cheilitis blog page, where he discusses his heroic round of visits to many doctors, including top national specialists, in sweden where health care is admirably good. i think that he got a lip biopsy.
b) it might be easy to assume that many people here are voluntarily acting like their own doctors or aren't too sensible in other ways, but there have been many interested, intelligent, motivated forum members over the years here (not to mention in the present day, of course!), and the lengths to which they have gone in trying to get a cure are impressive. just read over the forum threads of the past 5 years, and it becomes obvious.
i cannot see a doctor because i don't have health insurance, i have lost my job and don't have any money, and in the American system of health care, i cannot risk having any new medical records made for me which will create a "pre-existing condition" in that area of my body, which the insurance companies will exclude from being treatable for the rest of my life (they will exclude that area of my body, and they are allowed to choose which area to say that the cheilitis is related to -- it could be my lips, it could be my mouth and lips, it could be my entire digestive system from lips to anus...)
at a minimum, that area of my body would be excluded from medical coverage until 2014 -- and only IF the horridly crippled US health care bill gets passed, and that is still a big "if" (whether it will even get passed - i hope they will pull the whole plug and force them to start over.)
so, i cannot risk having an area of my body considered a pre-existing condition and not eligible for medical coverage, for the next 4 years, or for even longer. and, i can't afford american healthcare charges now that i am unemployed. so, i am prevented from seeing a doctor. therefore, i MUST become my own healthcare provider, and do research and treatment on my own. fortunately for me, research is one of my strengths, and in my life i've had several unusual medical issues that i have figured out on my own (whether or not i've consulted doctors about them), so i know i will figure this out too.
i learned much of what most doctors seem to have told most patients about cheilitis in the first week that i researched it, mainly thanks to this forum, medical journal articles, and a couple of dermatologist forums where they discuss amongst themselves their art/science.
sadly, cheilitis is an area where most doctors just don't know what to do beyond the few basic treatment approaches - and when/if those don't work, manyy doctors seem to be at a loss, and just try thing after thing, in order to give the patients something to try, but there are a core group of patients that just don't get better. some of them are so desperate that they end up on this forum.