Pokemon inside egg chances

Its just you. The game sticks to static ratios, nothing you do will change the likelihood of getting any specific pokemon.

I'm pretty positive where you pick up the eggs (biome) has some determination on what eggs/mons you get. When I get eggs from around the lake they have a way higher chance it seems of being water pokemon. When I get them from the stop near my house I don't get any water pokemon.

Depends on who you ask. There are firm believers on both sides.

Yes it is, unfortunately
I also get lots of the same pokemon as you but I live in a big city so I manage to find different eggs in other districts. Maybe you should try it as well.

I think I can make a fair statement that the eggs hatched are area dependent.

I'm living in The Netherlands and rarely hatch an Ekans, Sanshrew and Rhyhorn for example. I'm currently 2 months in Chile and have been hatching them more than ever.

In my opinion, this should provide enough evidence that the area where you obtain an egg influences the chances on a certain Pokemon.

Supposedly eggs acquired from around nests have a slightly higher chance of hatching that particular mon - seems true in my experience, but I wish it were easier to track eggs when picked up... Always hard to separate RNG from wishful thinking!

I highly agree with some of your findings.

I live north of Toronto - Drowzee had flooded the area on the game's release and yet I've never hatched a Drowzee (against). Simultaneously though, I also found any pokemon I saw none of in the wild to be very rare to hatch - Tangela, Ponyta, Grimer, Vulpix, Growlithe, etc... were all only hatched once each over the first several months. When spawns got better (i.e. I actually saw some of these nearby, still no Tangela though) I also started hatching these guys more.

Then further evidence, I went to Vancouver for a week and while there got a slew of hatches that I wasn't getting here much at all. Loads of Jigglypuff/Clefairy as well as Hitmonchan, Hitmonlee, Scyther, etc... (I got 4 10km eggs in 1 week in Vancouver, when I had gotten only 1 10km egg in the month prior).

I think egg chances are random overall, but your biome may have an effect. So let's say, you can't do anything to improve your chances of getting a Snorlax egg, but if you want Water pokemon eggs you can go to a water biome, etc...