I'm not sure how it is now but I wouldn't be surprised if it becomes more conservative in the future. Demographically rich old white men in isolated communities tend to be conservative.
Demographically, Silicon Valley is becoming less white
None that I'm aware of. Keep in mind that the author, Thomas Edsall, is very much a staunch partisan having written books like "Building Red America"
Even if there isn't, support for right wing politics for purely financial reasons is still worrying.
Donations, particularly PAC donations, are too tied up in tactical considerations to be evidence, in my opinion.