I am primarily a drummer, but am learning bass. Although I live near you, not that I'm being offered, but I wouldn't take the gig because there is some bad communication going on. You and the guitard bad mouthing the drummer when he is not in the convo. I just stumbled onto this thread today, but here are a few thoughts:
You live in Austin. There are tons of drummers in Austin. Many are gig ho's. No problem finding a drummer in Austin, but have you considered that they might have the same problem with you and the guitarist that ya'll are having with the drummer?
If you need a demo quick, but the drummer does good live, do what bands have done for decades and substitute for him in the studio. You'll have to pay $$ for a good drummer for this, but again, Austin is full of good drummers. Put an ad up at Tommy's Drum Shop. Or call Frosty Smith, the master drummer. He's been recording since likely before you were born. But no self-respecting drummer is going to do your demo for free.
I used to do alot of sub work for both gigs and recordings. Recording drums is something you don't learn the first trip to the studio. It takes time to learn how it works.
I say, give the guy a break if he is pulling his weight live. Doesn't sound like he has alot good going on in life but for the band. Get someone else in to do the demo, and then tell the drummer what you want on originals. Trust me, as a drummer there is nothing so random and difficult as being told by the band they don't like what you are doing with originals, but then the band doesn't give clear direction as to what they do want.
If the guitard doesn't wanna fire his friend, offer him this suggestion. Start a new band with guitard and a different drummer. Keep the old one going, just no rehearsals or gigs. You can maybe fit the old one in every now and then when your new and more improved drummer isn't available. No hurt feelings but your band keeps progressing.
Nothing to me is as funny as people in a bar band in Texas who make maybe $30-$40 a gig doing covers talking about "getting serious" and "making it". Cover bands, at least in Austin, come and go faster than Imelda Marcos used to change shoes. Until you're playing at Antone's, lighten up a little bit.
One caveat about changing drummers in Austin. Drummers in Austin wanna work, not be in a rehearsal band. If your band is not working enough, because of all the other bands you've got going, your new drummer will find someone else to play and make money with. He might still be available for you, but he will put priority into the bands that are actually "working" (and not for $30-$40 a night) and you will quickly become the band he plays with if nothing else is going on.
I've been playing in and around Austin and other Texas cities since the late 70's. I'm no Buddy Rich, just a normal blues drummer. I think I've been kicked out of one band (a jazz not blues band) in all those years. Communication is the key.
My final remark is about friends. Some of my best friends are folks I played in bands with over the years. Our musical relationships ended but friendship continued. And I value many of those friendships much more than the music we once played.
You know, you picked this guy despite his lack of modern communication devices. And remember, your new drummer may view you in the light that you view your drummer.