Context of this deck: strict progression style: cards up to A Journey to Rhosgobel included.

Key cards and play notes

Heroes

Éowyn is very important for progressing fast enough. She essentially always quests.

Legolas is important for handling the flying enemies from this quest.

Eleanor is key for handling the vicious treacheries from this deck. She often doesn't quest.

Other key cards

Lore of Imladris is key for healing Wilyador. He should ideally be used only when Wilyador has at least 5 damage (the maximum that can be healed after reaching Rhosgobel).

Lore of Imladris depends on Lore resources: Song of Wisdom is key.

More circumstantial cards

A Test of Will is useful when Eleanor canceled a first bad Treacheray.

Hasty Stroke is useful against some of the Shadow effects, which can be quite nasty.

Self Preservation is useful for keeping the all-important heroes in play.

Miner of the Iron Hills can help with Caught in a Web, in case Eleanor doesn't handle it.

Some cards are included so as to handle the flying Enemies, Winged Guardian (and Radagast, Radagast, along with The Eagles Are Coming!, which can help bring them in), Rain of Arrows

Cards that may not be key

Song of Kings is only there for Steward of Gondor, which is itself here for generating enough Lore resources for the more expensive Lore cards. But I rarely had any resource problem with this deck so maybe these two cards are not needed.

Development notes

Deck abilities and characteristics that can be relevant to the scenario A Journey to Rhosgobel, starting with the most important ones:

• This scenario has significant direct damage in the form of Treacheries (A la Merci du Nécromancien + Blessures Purulentes is a combo that gives 3 damage to multiple characters in no time). Treachery cancellation is important. For the same reason, Heroes (or even Allies) with enough Hit Points can be very useful. ⇒ Eleanor, the Spirit sphere, and A Test of Will are good candidates. Another tool is Encounter deck manipulation, as the above two cards seem the only ones capable of cancelling a revealed Treachery: Denethor comes to mind; cards that handle Enemies like Forest Snare might also be good (but it's a Lore card).
• The voyage goes through a region infested with flying nasties. Having attacking or defending Eagles or characters with Ranged is key. This strongly points to the Tactics sphere, as it is the sphere with the most Ranged cards (in strict progression style). Being able to inflict direct damage seems key, too.
• It is important to rush to Rhosgobel (Quest 1) and then to quickly look for Athelas (Quest 2), because the environment is very inhospitable, so high willpower is important. This points to the Spirit sphere.
• The region that we go through is quite unhealthy (Blessures Purulentes,…), and more importantly, while at Rhosgobel, healing Wilyador is important. Healing is important. The Song of Wisdom might be useful, here.

Additional considerations:

• Eleanor could be usefully paired with Unexpected Courage, for more flexibility.
• I do not have much experience with this scenario as of this writing, but Hasty Stroke might come handy, as the scenario seems to lead us to inhospitable places with direct damage.
• Landroval is expensive, but the very unhealthy nature of the journey (with lots of direct damage) makes Landroval potentially quite useful, as it can save a hero. Another difficulty is that it belongs to the Tactics sphere, while the Spirit sphere (with Eleanor and A Test of Will) seems very important, but Denethor does too. However, Denethor seems less important, as the two key Spirit cards might handle Treachery removal well enough. Maybe having 2 Tactics heroes would help with these two issues? Legolas having Ranged, it looks like a good idea to not had Denethor.
• Landroval and a Dwarf hero like Gimli make Brok Ironfist a possibility (with a Song of Wisdom, if needed).
• Radagast is expensive, but it is Neutral, and he seems appropriate for healing the various eagles, including the wounded Wilyador.
• The Westfold Horse-Breaker could be useful for helping Eleanor to handle a Treachery even if she is helping with some other task already.