OTOH, shield wall in the far east was giving me +33 to defense and armour.
Between mithril plate, shield wall, a decent shield, and massive armour training, "normal" monsters didn't give me much trouble. It's nice to hear the tell-tale thunk of an arrow hitting (or missing) me, and realise that I don't have to care

I didn't advance riposte until late-ish (moria, maybe), when my dex was already quite high. So at level 3, it was giving me 60% chance. I didn't advance it any more, because level 4 also said 60%. If you're taking a long-term view, more than 3 levels is pointless.
1 level in assault gets me a guaranteed two critical hits (assuming I hit). Shield damage is nice, but critical hits with my main weapon seem like the main benefit, so I never advanced it beyond that.
The juggernaut skill doesn't give a duration.
I didn't take Shattering impact -- it didn't seem like a good idea. Despite shield wall / heath / high constitution, my ability to deal damage still exceeded my ability to take it. I don't know how high the percentage goes, but I could see myself doing 100 points of damage to myself with each hit, which didn't seem safe. If I'm surrounded by grunts (e.g. drakes, regular uruk-hai, assassins, archers), then I can kill them easily. If I'm surrounded by nastier foes, then I really want to get out of there, rather than smashing everything in sight plus me..
Dragons and mages and wyrmic uruk-hai burn all my scrolls to ashes. An indestructible form of phase door would be _really_ handy.
Off-screen monsters are a pain. Is there any way to look around in windowed mode? Perhaps the monster display could, at least, give an indication of direction (N/S/E/W).