Can this be added to a house wash mix like you can do with EBC Glide?

Titan Glass Gleam 4 is formulated specifically for glass, so we would recommend EBC products for house washing. 

can this be effective to minimize condensation on the outside of a window?

There is no product that can minimize the actual formation of condensation on the outside of a window as that has more to do with environment than the glass. However, you can try to use Clean-X Invisible Shield, which will minimize hard water spots from being left behind on the glass from that condensation.

does gg4 ruin painted walls?

Titan Glass Gleam 4 Soap is safe for all surfaces, however we always recommend to test a small surface before a full application.

How do you put it on your window do you just like apply it as it is mix it with water or what

Hi there, the recommendation is to add 1/4 fluid ounces per 1 gallon of water. You mix it together in your bucket first, then take a complete stripwasher, soak it, ring it out, and scrub it on the glass.