I don't know about the head change, and as much as I like the sound of analog over digital, I think you might be best mixing down to digital 2 track, if you want other people to be able to listen to your music. The only reason I say this is, most people listen to CD's now, which means that at some point you have to make the digital conversion.
I mix concurrently to digital and analog - digital for everyone else, analog so I can listen to it and enjoy it myself later. I've also tried mixing to analog (1/4" 2 track), then tried putting that to digital, but have found I lose more than I gain. The sound can be fuller, but there's apparent hiss so when you go to compress it in digital you run into all kinds of problems.
Just some thoughts, sorry I can't answer your specific
Tascam 44 questions, but even mixing to just two tracks on the 44 wouldn't be so bad for the equipment you have. Doing that would also enable you to use the other tracks for a second pass around the tape, for alternate mixes or whatever. A pretty good, cheap mixdown deck is a
Tascam 22-2, which is what I use. Only thing I wish I had on it sometimes is noise reduction.
-MD