I'm thinking about installing "Ultimate Deadly Encounters - The Way of the Dovahkiin". Trouble is I can't find the installation instructions amongst all the bumpf. Don't get me wrong, it's all very well written and made bumpf, but of little use for the basics, like installing the mod. For example, do I need to install it at the beginning of the game, or can I install it anytime? Is it basic plug 'n' play for someone using MO? Incompatibilities?

I think it's standard stuff when it comes to installing big overhauls on existing saves--start a new game or you'll have a bunch of problems.

http://sotrealms.enjin.com/installation

Ahh, I see, it's one of those mods, so complex that you have to have it from the beginning. Hey-ho, no big deal. At least I've got its add-on mod, where enemies can follow you from one cell to another. Pretty neat in itself!

Yeah, it's also really, really unstable and I don't care for some of the things it adds. But the crazy man in me wants to give yet another game with this installed a go.

It's a great mod.., If you only read the stories and immerse yourself on their website. But ask yourself, do you want a mod because of that, or because the mod itself is great?
The mod in my opinion is, as the previous poster already said, really unstable and I'm deleting it from my next build. The stuff it adds isn't really worth the hassle in my opinion. They make it sound better than it really is.

Also, starting you whole game over after every small fix is a big no go for me too.

That's good to hear, because I don't want an unstable playthrough. I want as many new things as I can get whilst keeping the game smooth, 'cause I want my character long term.

I you want new things I would suggest Immersive Creatures and Immersive NPC's, top that with an AI enhancer like Revenge of the Enemies and some good ol combat mod like Duel and Combat Evolved and you're good to go. Less mods is better and more stable.