"Yet another disassembly of JSW" - heh, I wish I'd used that title for the disassembly! :)
It is the only complete disassembly of every byte used by the game, though (that I know of, anyway). Same for the MM disassembly, too.
There is a single POKE (equivalent to your three) that stops the clock and gives Willy infinite time:
POKE 35408,24
You can also stop the screeching noise on the title screen with a single POKE:
POKE 38635,0
And to stop the screen colour cycling while the intro message is scrolling with a single POKE:
POKE 34997,1
(What can I say? I like single POKEs. :) )
Nice site!
If you're interested, and in case you weren't aware of them, on your Links page you could add the complete disassemblies of Manic Miner and Jet Set Willy:
Manic Miner
Jet Set Willy