I found that my solo Silvan deck really lacked defense, so I dumped my waify third hero in favor of a giant hairy bear!
Beorn is of course the primary defender in this deck; no one else can take a hit like he can. In fact, many of these Silvans crumble after a single point of damage, which can really wipe out your board (save your A Test of Will for those nasty treacheries that deal one damage to all allies). Beorn will inevitably die, but Celeborn and Galadriel aren't giving up their pet so easily: a bit of elf magic with Fortune or Fate and boom! Zombie bear.
The primary objective is to get Nenya on Galadriel to help with questing, and to give her the icon that will allow you to Tree People Silvans in and out of play. O Lorien will reduce costs on your allies, and Errand-rider moves your resources where you need them (Beorn in particular will tend to have extra resources lying around, and you certainly don't want him to die with unspent cash in his fur-lined pockets).
Horn of Gondor isn't as good as it used to be for Silvans, but playing it on Galadriel means that when an ally (or Beorn) does die, she'll be a little further along to affording that expensive Fortune or Fate.
With Light of Valinor on Celeborn, and Beorn not exhausting to defend, and Galadriel/Nenya sometimes not needed, you may find yourself ending the combat phase with 2-3 unexhausted heroes: the perfect situation for Peace, and Thought. If you haven't used this card yet, trust me: drawing 5 new cards into your hand is even better than it sounds :D
I was just looking through Celebor/Galadriel decks to see whom people have paired with them. I like the idea of Beorn! He can certainly solve a lot of problems. Spending for that Fortune or Fate with only one blue hero is going to hurt. Is Galadriel where the horn goes?
I do need to comment on your use of Peace And Thought...it is a "refresh action," which specifically means it takes place AFTER all your heroes have already readied for the next round. So if you use it, you will have used up their actions for the NEXT round, not the one you just finished. Far less powerful this way, sadly.