I always have the animal's well being first on my list of priorities, even above my own safety. If the animal is getting very stressed, I release it (if I have some scientific work to do, I try to do it as quickly as possible).
Do you catch any snake, even if it's the 24th ammodytes of the day? In our team, we have some differing opinions about that sometimes, because some are fanatic snake hunters, who like the kick of catching. Good or bad?
Sometimes I try to catch everything I find, sometimes I just stop long enough to see what it is and then move on. Depends on what it is and the habitat I found it in (if it's a muralis only a couple of cm away from his hole, chances are 99.99...% I won't even attempt to catch it). Also if I'm feeling lazy or not.
I don't have tongs, I rarely use hooks (even rarely for flipping stuff). I mostly do everything by hand (with thick good quality gloves on, of course).
What would the impact be of catching a snake on the survival of that animal?
Unless you cause an injury that in itself can be fatal or can cause something else which could lead to an increased chance of dieing, I don't think it would have such a big influence.
Yes, some stress out more than others, but if you're careful about it (if the animal won't calm down- release it; if it does- don't get it worked up again), again, it shouldn't have a big impact.
How do you feel about entering private property while herping?
Over 90% of herping on private property I do is on the hills where I have my vacation cottage. There a lot of weekenders have their cottages and the villagers have their orchards, vineyards, gardens... I have their permission for herping on their land, so I have no worries.
If I happen to end up on private property elsewhere, I always do my best not to disturb anything (i.e. flowerbeds).
Also with habitats- if there's something that can be flipped, I flip it only if I can place it back the way it was. Especially with something that's moist underneath.