Stay away from Amsterdam.[sorry]
Is 1.g4 playable to avoid the dutch?

The thing about 1.g4 is it's not an improvement over 1.g3.
So unless you're hoping for black to fall into 1.g4 traps, just play 1.g3 instead.
Not an improvement but leads to vastly different kind of game. W has space advatage and timele g4-g5 may make K-side Kn bit problematic. So people playing g4 probaly would not see g3 as oon alternative.
Then again if one is afrais of duth why not just e4/c4?
No doubt that a philosopher would find bright points even at white's worst move one option (comparable only to 1.f3). In reality, 1.g4 is a viable option only at hope chess, and that's all.
I never really liked it. Black can either play slowly with 1...e5 and try the ...Nh4 thing or play 1...d5 and sac a pawn. Black seems to have all the fun imo. I'm not really sure why you wouldn't just play 1.g3/1.Nf3/1.c4 or something and try some d3 setup if you know your opponent wants to play the dutch. Because you certainly aren't going to just play natural moves after something like 1.g4...