Hi - I'm returning to LOTR after a number of years away.

My local area seems to be playing 500pts so here is a provisional list I'm looking at

Eomer KoP + armoured Hoss 130
5 x mounted royal guard 80

Erkenbrand + horse 75
6 x Riders of Rohan + FV bonus 84

Eowyn + Armour 35
10 x warriors inc 6 x bows 66

Merry + Shield 30

The idea is that merry tags on with eowyn to give use of his might when losing priority. 2 x punchy mobile formations to take on whatever is presented. I realise model count is down but it gives me chance to do a decent paint job - locally the fellbeast is a frequent attender so a counter to that would be good.

just so you know the riders of rohan or heroes don't count towards the bow limit, so you only count up you infantry model from the list you have posted, the limit is 1in3 rounding up, so with six bows from ten troops puts you over by 2(rounding up gives you 4) so maybe change two of them for guys with shield and axes if you can, personally i use infantry for fighting just with the aim to tie up as much of the enemy troops as possible while the riders do the shooting and flanking

edit: also if you change one of the riders for a mounted outrider, it will give a spare point for another piece of equipment on your infantry, and they have a cool rule regarding standfasts and better shoot value than a regular rider of rohan

As for you nazgul issue, i dont know how you really deal with these guys, other than get in close as possible and send wave after wave of men at it until it burns will out - but what ive seen on gbhl podcasts and others, they can pretty hard to take down - without magic or monster you might try get a single troop ideally infantry at a time into combat with it, you may lose a troops but you are slowly chipping its will down - and hopefully it will hit that magical 0. But im sure more experienced players have better ideas on how to cope with one -(hopefully this hasnt overstepped the mark) good luck with it dude - rohan are fun army to play (even though i seem to always get wiped out when i use them)