Well you don't have to delete everything. 32GB or even 64GB is plenty for anything you'd want to do in the short term (within days or weeks), unless you're super finicky and have to have random things right now.
If you're planning a trip, you'd download your game, gps maps, and reading/listening material ahead of time. Your data plan would be more than sufficient to fill in a blank here and there and let you opt out of paying for hotel wifi (even though on my month long road trip through the American South I had free wifi at every location I stayed in even in cheap motels, though I'm aware of some higher end places that still do charge extra for wifi).
As for your 2600 pictures and 35GB of apps, do use them all everyday? How much of that have you not looked at or ran on your phone for more than 1 week? More than 1 month? Can't remember the exact day when it was last used? I bet you can cut that down A LOT if you stuck to only things you look at and use.
The point isn't that going cloud based means you're downloading all your data all the time, just that it allows you to keep just the essentials you NEED while data is there for the occasional song you want to listen to but wasn't on your playlist, or downloading that one obscure app you found yourself needing. A 2-4GB plan is MORE than enough for that.
I use just over 1GB per month and I download occasional podcasts on the go, listen to talk radio live streams from time to time, check email, download apps from time to time, and use google maps heavily. I even occasionally buy a song from iTunes on the go. So I know this is possible and feasible.