Wiggles, "Would you ever", is, to me, a very broad question. As with anything.. it would depend.
I've known people who have had sex on the first date. I've never had sex on the first date, but that's just me.
On the subject of tickling: It would depend on how well she and I were getting along, and what else was going on physically. If we were really attracted to each other, and were making out, a lot, etc, then maybe I would. However, if it was just the usual first date of "getting to know her", discussing our interests, etc, then no, I wouldn't. I'm not that forward of a person. I probably wouldn't even ask a girl if she was ticklish on the first date, unless something happened that caused the subject of tickling to come up.
Mitch