In amongst all of the above he does this really bizarre stuff....this is a rehearsal and he'll get up and say something like "this is the last song we're gonna play here tonight" (repeat...this is a rehearsal).....and when we end the song he'll say "thank you very much" (during a rehearsal) like some kind of demented, twisted Elvis.
He's not a particularly good singer either...but the other fellers seem happy enough with him so I'm happy to give him time....this is the first band he has ever sung/played/been in so I have some sympathy for the nerves thing,
It's actually a good
thing to practice things that he would say at a gig. Have you ever played a gig, and at the end of each song there is that awkward moment before the crowd realises the song is done, and starts clapping? Saying "thank you" right after the band hits their last note is a clear signal to the audience that the song is over. This isn't necessary for a big concert where the whole audience knows where the end of the song is anyway. But for what you're doing it's a good idea.
Being a good front man takes practice and experience (I'm not one, but I know good front men/women, and bad ones too) and I bet what makes the difference is that the good ones are prepared, and may even practice the stuff they say between songs.
And it takes a much larger set of cahones to get up and sing in front of people, I know it's something I couldn't do right now. Sitting behind the drums is easy, for the guy standing out front, he needs to be as comfortable as possible.
But he should at least learn the lyrics. Make sure he knows that he can't have lyric sheets at a gig.