Hey man, see the commentaries here as suggestions and don´t give up of allways improving your building hability. More than all, if you have a crazy ideia and thinks that worth a shot i say go to it! Even that mey be not a great all-mighty-powerfull one the fun is what counts more at the end. Obviously the people here just intend to give you advices to improve your deck generally with the competitive power in mind, so i guess they would be welcome and their critics can be very useful in many ways...
I don´t know a crap of Forestgul or beating Down Guls so i will restrict to some dwarf commentaries... but i would agree that, if you are looking to improve your chances of win you should reduce it a little bit.
Endurance of dwarves looks very good (and can be) but keep in mind that expanded shadows tend to have lots of condition discard and if they manage to exhaust your companion they can simply kill your companion even if him/her was even assigned to a skirmish (as simple as playing a minion or using a manuever event...) so it´s a thing i always worry about (prefer the artifacts that adds vit cause they are far harder to discard).
Gimli Battle Axe, VW and
Armor of Khazad can be good option to your dwarves. The first one help you against unnespected surpirses while boost the last (just don´t abuse it or you may have some trouble!).
NPNS can be a very dangerous way of cicling, maybe just cuting some cards from the deck would work better.
Dáin Ironfoot can be a good companion to throw in your deck, maybe at the starting fellowship along with Durin.
If you cut the 4
NPNS,
Endurance of Dwarves, one
BRC, one Harp and one MH and add the Gimli Axe, Dáin and the armor you should make the deck around 35 cards which seem to be a good number for a "non mad ciclying deck".
If you want to stick with
BIF for the Nazgul you have to search ways to discard conditions and possessions and add some twilight with your Guls, then it can be more effective...
Hope i helped some way.