My last game there were so many Dread Hamsters in an area of wilderness between kingdoms that I literally couldn't kill them all. I had a plagued Ranger that I was keeping up with the Shrine of Sirona and every turn he would kill a hamster pack...he did this for about 20 turns and leveled from 13 to 15 on hamsters.... and there were still stacks of them roaming around. They seemed to be breeding as fast as I killed them!
Then the game had a reproducible CTD so I couldn't continue it. On a side note, I opened up the game in world builder and I tried to identify if something is being built or happening that would cause a CTD. One thing that IS strange is that the elven kingdom's cities have nothing being built in any of them, so maybe this is the problem? Too bad, these games get really interesting and it would be nice to finish one. If anyone has any pointers or a link to a thread that shows how to troubleshoot a crash, I'd be interested. This is an awesome modmod, it just needs the quirks worked out.
I was going to start a thread on Hamsters (just what this forum needs

), but since you mentioned them here I will add to what you wrote.
In all my previous games the map was filled with Lizards (all kinds) and Sabretooth Tigers. This game is teeming with Bunyips (in small bodies of water) and those damn hamsters. A couple of points on them:
1. As you mentioned it is really like playing whack a mole with them. Kill one and one or more is back immediately - spawning in the same place you killed one.
2. They seem to give both the Plague and Poison. I had a unit that needed 30 turns to heal and one that was Plagued was dead in the water because I was far away from priests or getting Divination. I was lucky to find the Pool of Tears, however.
3. The worst thing, though, is they have the Marksmen promotion and target the weakest unit. In this game you are nuts if you send out a single unit out with these animals. Even with more than one, one Hamster will hit a unit and die, but weaken it for the next Hamster who will use Marksmen to kill it. I lost a number of units this way.
4. In my game Hamsters wiped out 3-4 cities (the message was 'Animals destroyed a civ' or something like that and I know they were Hamsters). These things not only head directly into cities to attack (especially unescorted Workers) and I've even seen them spawn inside civ borders.
5. One definite balance issue in the game (I think this goes back to FF) is that the AI VERY often will spawn one or more units, um, intelligently next to yours. For example, your unit is wounded and a small stack of units shows up next to your unit immediately. Well, this happens a lot with Hamsters who are constantly attacking you with an age of 0.
6. The Hamsters are really tiny and sometimes hard to see, especially in terrain.
7. Incredibly, I came across a Hamster Stack - 4 Hamsters in a stack. No way you can deal with this with their superpowers - Plague, Poison, Marksmen, etc.
In sum, these little buggers are quite the challenge if you happen to get them in your game. I thought Sabretooth Tigers were tough, but these Hamsters have them beat IMO. Still, as I mentioned in another post, I just love the challenge and play with the animals as they are now. I hope they don't get nerfed too much in the next patch.
As to the CTDs, yes, they are very frustrating in that it seems impossible to finish a game. I save after EVERY turn. Going back to previous saves, intentionally changing what I did, doesn't seem to work for me. Once I get the CTD and repeat it several times after re-loading, I know I am done and it is time to start a new game again.
It is really a quandary whether to play a stable FFH, FF, or Orbis when I know I can play larger maps and finish the game, or enjoy the 300 or so turns with RifE knowing that it will eventually crash and I will not finish.