Do every game on steam go on sale during summer sale?

Almost every game does. Practically every game gets some discount, and some get temporary bigger discounts, but games that don't get discounted at all are VERY few.

Damn near every game does. Not ALL of them but most. Payday 2 likely will.

considering it's this close to summer, it might not, if it does go on sale during summer... it'll probably be around the same as the price it's currently at since it's quite popular, dlc wise, if the game goes on sale, the dlc will follow.

No, but Payday 2 most likely will be since it and its predecessor have always been part of sales.

Activision games wont go down like ever.

Other than that, it might,if its not on the sale, ill go down again, sometime.

Game wont go that low anyways. Just get it now.

Almost seems like it, but no. Many of the newer games will at a lower discount compared to other games, a lot of indies probably will too, a lot of the older franchises, but not everything. Sometimes you can spot a pretty epic deal though.