I would like to offer the following suggestions.
A natural disaster such as earthquake to knock down inactive castles to rubble. Eventually nature can reclaim the rubble therefore removing inactive castles?
An Amnesty for players to hand over ALTS? - reward with troops/sapphs. This would also remove castles and maybe help to level the field a little.
Removal of inactive leagues, or at least moved into "limbo" and reactivated if their is league activity again.
League merging. Their are far too many leagues and they need to band together. Leagues don't merge because of loyalty to their marshal and/or fear of losing the achievements they as a single league achieved. A system of merging with a dual-marshal leadership and combination of previous achievements for the benefit of a merged league. Their can be a X-number of days opt out option just in case minds change.
A language translation in chat would be useful. I wish to read in English therefore and automatic translation into my preferred language would help remove barriers of language. Translated languages could be in a different color to highlight that there may not be 100% exact translations.
League rewards for taking in new players and helping these grow to a certain level. This would reward the small leagues who are training the future of Stormfall.
There needs to be segregation of coiners and non-coiners. No sane person is going to punch above their weight. If i have 1 million troops i am not going to attack a player with 100 million troops. This makes the game boring for the both of us. Have no suggestion but it needs to be addressed.
The Battleground system is a mathematical mystery to me. Simple folk like me do not and never will understand it. A game is not fun if you need a degree in Astrophysics to understand it. Make it workable for those of us with a low IQ?
Its a war game and its all about troops. They take too long to produce, they die too easily and can only be revived with sapphs therefore real money. The non-coiners will never do this. So how about speeding up production with supplies. A % of troop loss can regenerate or be bought with supplies. Revival with supplies. If you put in the time raiding the get rewards for your time.
The league message for members to read is only a few hundred characters. When a new player joins it would be good if they could open a page there with a few rules for that league's style of gameplay. The game is a little scary at first and having some guidance at first would help. Most new players wont use chat therefore it hinders their growth.
Regional chat where i am is a wasted feature, maybe a stormfall wide chat instead? This would require a language translator as previously mentioned and a moderator to keep it "clean", but could make if more fun.
The My Tier rewards was a good addition, however i consider myself pretty active and i still rarely come close to good rewards, maybe revisit your parameters there. Getting something free every now and then will help keep interest.
Its a war game, how about a real player verses player option. 2 castles, my off verses your off, my def v yours, or my dragons v your griff's, could be scaled up to league V league.
The benefits gained from Relics are quite poor. If i could get a 100% increase in something for a 24hr period i may be more inclined to risk my troops. Even a few sapphs reward for successful attack would make it a more attractive process.
Some new personal feats of valor for the people who have achieved those originals, things Alt accounts would struggle to achieve to help you continue to reduce the appeal of Alt accounts.
The rewards for league achievements are not worth the effort. Gaining points for leagues at war has simply led to leagues fake fighting their Alt leagues to achieve these. This is pointless and needs addressing.
The Alter of Woer becomes redundant after a certain level, you just don't need the supplies, maybe if it provided sapphs for every week it stood it would make people buy it and want to keep it, therefore making it a target for attackers.
hmmm sorry i got carried away with suggestions.