I don't believe fiberglass fenders are necessary at all for 35" tires, it's actually not a big tire. Again, it all depends on what you're using the vehicle for. Mine is a daily driver and a trail rig, but it's not for show. Cutting fenders and trimming fender liners would be more than enough for me to run 35's, as long as the BMC was done, proper offset wheels were used, etc.
I understand if guys have newer, low mileage rigs and they want to keep them looking minty fresh, but i'm way passed that stage in life. It's a tool and i'll modify it to do a job. At this point, the pinstripes, dents and missing pieces are just trail badges. While 33's aren't big and I won't be a rock crawler anytime soon, they are a good enough tool to go most places I want, 35's will just make me less picky on what line I take, and leave my skid plates with less damage at the end of the day.
Washer fluid bottle relocation is easy as long as you don't need the same capacity bottle. It can me mounted literally anywhere and you can buy any bottle you want, or retrofit a milk jug if you're desperate (kidding). Just buy some rubber tubing bulk, some wire to extend the harness, find a spot to mount a new (smaller) bottle and put the pump in it.