So ADC Nasus

Nasus is already easily bullied in the top lane. Add an extra opponent in bot to harass him... ugh. Miserable.

Maybe if the opponents have a passive melee support and you have an aggressive support that zones them off of you, but even in that scenario, it still seems awful.

Dude, it's broken. Let them push it early, get like 75 stacks, come back with armor and one shot their carry. G mother fucking G.

No. Pair Nasus with a Soraka support and it will be pretty much impossible to keep him from stacking or force him out of lane, so it's not a matter of whether or not he could lane bot. He could IMO.

The issue is that come mid game when your team needs sustained ranged DPS all you have is an under-leveled Nasus who is going to be kited in team fights and made irrelevant. If your team has something like a Vayne top this might not be an issue, but the under-leveled Nasus still wouldn't be useful. It would basically take Nasus even longer to come online than normally. Furthermore, a lot of pressure gets put bottom lane in the form of dragon fights and general jungler activity. Nasus can't really help with that shit as well as an ADC can.

He is melee and pops like a balloon unless building tank.

I've had a full crit nasus destroy our team once. his Q did some 2.5k damage. i did it once too. same thing crazy shit but that was when triforce had crit. its harder to do now