I got all my collectibles with level 2 exploration, although it took a looong time to find that elusive last beetle and stone, but it happened. I opted for level three exploration over the third tech level ... really, unless you set your sights on that right away and save up, which is hard when you are trying to feed your tribe and get farming out of the way, it is not needed ... I don't see any benefits beyond making more tech points that at this point in the game you really don't need unless you want to pad your stats.
I also have so many healers going, and so many very happy and healthy villagers, that I figured why make a hospital if there is no one sick enough to use it? Someone sneezes, and immediately I have four or five (or MORE) rushing to their aid. Longevity of the villagers would be a plus, but even on level two med, I am up to my ears with villagers --- my tribe increased from 42 to 71 within a few hours of keeping it on normal time ..(I usually play in 1/2 time but forgot to flip it back when I went to work LOL) ... so why do I need the extra fertility benefits? LOL ... and there are a LOT of 13 year olds I will be having to direct training for in a very short time from now, having 29 kids all at once certainly makes for an eyefull. Lots of playing tag, jumping around, and watching them "attend lessons" ... makes my day

Most of the stuff you need come in time ANYHOW ... if you have the patience to wait until it is time to happen.