Absolutely agree with this. When it's just pouring down I'm not super-enthusiastic about commuting in, but I have to regardless as it's my only way to work save having my wife drop me off (which I haven't yet resorted to). About two minutes out the door, however, and I'm completely fine with my decision to ride. It's actually somewhat fun.

For fogged goggles, there are anti-fog applications that can help. I'd maybe even try standard Rain-X and Fog-X for the respective outer/inner surfaces.

For slipping, I'd probably just change tapes, though I haven't noticed any problems with my grips/tape.

And for slipping, I just tend to go slower, especially on the turns. No real insight on particular tires that perform better in wet conditions. I do use 28s on my cross bike and 2" on my cargo, so maybe forgo 23s or 25s if that's what you're running.