Exactly. TAZ even used WPs inside walls to get bots around corners on extremely narrow ledges in cs_bigwong, I used several WPs inside walls in cs_waterside to get bots to walk around open doors sticking into the corridor instead of running into them, etc. etc. ... Like SF says, it belongs to the "tricks of the trade". And even if most other issues could be fixed, I wouldn't know a way to avoid the ladder bug without going noclip into the walls and placing a WP there...
Ah yes, de_bridge... Actually, it's not very hard to get bots to walk up the bridge and camp on top of it, but given the enormous size and wide open areas of the map, it costs loads of work and time indeed... I have that one waypointed for the old PODBot, and as far as I remember, some more difficult bits were a) getting the bots to camp on top of the rocks
next to the top of the steel bridge and b) that stupid underwater passage to the 2nd bomb spot. Not to mention the jumps from that higher passage in the rocks over the lake to the smaller bridge (2nd bomb spot) and back... Did you get that underwater passage to work perfectly (i.e. w/o bots losing health) in both ways? I gave up after 7 or 8 attempts...