I can get the heebie jeebies with heights, particularly so on the above trip. I was last down the shaft so at 40m intervals I could see the lights of the other 5 members of my group with the furthest one nearly 200m straight down! The rope is bolted to the wall every 40m or so, so once someone's changed over at the belay, the next person can start their own abseil.
Further along in the trip there is a tightish bit - "La Turbinia" where the hitherto massive cave narrows down to a squeeze so the wind really roars past you. As well as the noise, back then we had to use naked flame carbide lamps for long trips and the wind would blow the flame out. There's a short abseil half way down the The Turbine which is sufficiently constricted that you have to have your abseil device at head hight on a short line as there's no room to have it in the normal place at your waist. It's only a short squeeze, but quite committing. There's a rubber dinghy section later on too; an epic trip altogether
Regarding the "getting stuck" scenario, it is objectively a very low risk - perhaps a valid comparison might be the risk of lightening strike for a cyclist, thus a non-zero risk that you might have to consider in some cases but not something particularly to concern you as a rule. I've been "temporarily inconvenienced" in tight passages a few times, but as I once said, to the amusement of my comrades "I'm not stuck, I just can't get out", after rather foolishly blocking my exit by moving a large rock. I've never felt claustrophobic in a cave, but did get a claustrophobic panic attack in Ikea on one rather unpleasant occasion. I ended up barging down the up escalator to escape but had managed to hold it together to avoid kicking open the fire doors. In retrospect I rather regret not doing just that, given I'd been deliberately manipulated into the state I was in. Hey ho
