Thank you for all the feedback I've received. I've managed to find and fix quite a few bugs, both with single cards and the system itself, here is the list off the top of my head.
1. Sanctuary now heals 5 rather than 6 wounds.
2. Ulaire Cantea can now discard weapon borne by character in its skirmish.
3. When card is attached to your opponent card (i.e.
Black Breath,
Blade Tip), the display no longer hangs, which prevents you from playing when you reload the page, it still does if Frodo is killed, will fix it later, as it requires a bit more changes... but the game is over at that point anyway...
4. When player moves, the next site is now correctly played from opponent's site deck, rather than from free people player's deck.
5.
Aragorn's Pipe supposedly didn't work, in fact it did, it was just a bit complicated to use it. Pipes have the magical "spot X" which means you can choose to spot less than all of the matching cards, therefore the game has to give you a chance to choose a different number. In the past, the default was "0" for this action. Right now the default is always logically chosen based on the card. So if it's a beneficial effect (as in case of
Aragorn's Pipe), the default will be maximum possible, but player will always be given an option to change it via popup, similar to the one where you choose number of burdens to bid.
6.
Mithril Mine no longer allows Shadow player to play FP possessions on opponent's characters from discard.
7. Game no longer freezes when player has
Wariness or any other event card that responds to "playing card X" in hand, when a new site is played.
8. When you move to site 9 in Regroup phase, you no longer instantly win. You actually have to go through the Shadow...Regroup phases again. But I got a free win off that once, haha.

9. If you have finished one game, you should be able to join another one, even if the previous one is still displayed in the Game Hall as "Finished".
10. Added lots of stuff to Deck Builder (you might have to reload the page while you're in Deck Builder) - counts of cards FP/Shadow are displayed once you have ring-bearer, ring and sites chosen. Also the validity of the deck is checked and displayed. The collection on the right now also allows to filter the cards based on Culture. The buttons with images look bad, I need someone to do nicer icons with transparent background - please...
Once again, thanks for feedback, and keep it coming.
I've managed to play a couple of games and it seems that most of the stuff is working as intended. The game might require a bit of getting used to, especially the fact, that you have to click on the optional effects for them to work, even if they don't make sense to be optional (
Goblin Runner,
Goblin Scimitar). But it plays fine, once you get used to that and configure the "Settings" tab to your liking.