If your looking for a Hustle Castle Forum there doesn’t seem to be an official one. You can check out this Hustle Castle Wiki though which has a lot of information on various things. If you have any questions or added info you can leave them in the comments.
Hustle Castle FAQ
Best Way To Get Equipment – The best way to get good gear for free players is to make it yourself through crafting. This way you’ll be able to get what you want instead of relying on random chests. You should start out replacing items that are weak or underleveled. You can get shards for crafting by breaking down items that you don’t need anymore.
Classes – You might not have realized it but there are technically 4 classes. They are the Warrior, Archer, Mage and Archer with melee weapon. When you equip the Archer with a melee weapon it will dramatically increase the DPS and max power though defense will be on the low side. According to the poll below and from experience the mage with it’s revive spell that comes on weapons is a must have as it let’s me beat players that have a higher squad power. Having more then one reviver can be a big help too. The warrior is a must have as a tank and will keep the back row save most of the time. The archer seems to be lacking slight when it comes to damage output since the mage can hit multiple targets. The archers only real benefit is that it can attack from a long ways away.
Easier Stages – If you having a hard time completing a stage you can wait awhile and them enemies and difficulty can change. This can also be done for invasion when they are to difficult and cant be beat. Just wait a short ime and the enemies and and power level should lower.
Forum – This page is not a forum though it does have a small faq. You can find lots of info if you visit the Hustle Castle Wiki.
How To Delete Dwellers – When you start to replace dwellers that have low potential your gonna have to delete some to make room. This can be done in the inventory screen by tapping the button to the right of the character. This is also where you can rename then with something else.
How To Merge Rooms – When you put a room next to another that is the same type and level they will merge into one bigger room. This is useful for collecting resources as you’ll have to tap less. When merging the hospital you will only increase space. You might want to unmerge rooms to have a cheaper upgrade cost.
Pets – Pets are for decorating purposes only and will not increase any stats or help when the castle is attacked. They could of at least included them in the defense of a potential resource thief.
Reset – If for some reason you wanted to start over the developers didn’t make it very easy. You’ll have to attach your game to another account then start a fresh install under the old account which should be empty and new again. This will have to be done if a new install didn’t start things over for you.