I've been wondering where you've been!!
Good to hear you're well enough to get on the computer.
Outside of going through each mission to change the weather conditions, I don't know of any other way. But really, I've never looked.
I don't know about the mini-tweaker, but the "Silent 3ditor" (found
HERE) pretty much has taken the "tweakers" place. It will work with the SH 1.4 version.