Chains-- Having to hold the chain for however long leaves you completely defenseless, and one hit makes you drops the chain; and the defender respawn is so close to the chains that attackers have zero power over it. The transition between the water level and trap level is rather sudden... it would be nice to have a 2-3 sec. warning while the water is draining to find a safe spot.
Fireball Spinner-- It takes an annoying long time to get past it, so a few ideas: (a) 3 arms instead of 4; or (b) allow people to walk through the fire after being hurt; personally I wouldnt mind taking one hit if it meant getting through faster. (c) [wouldnt work for current layout, but possible future idea] give it a larger radius and speed it up.
Spikes-- I do like having the alternative route along the sides as long as youre fast enough. But the two spikes at the bottom are kinda unfair; theyre on a short track and its right in front of the respawn door.
Defender Respawn-- the largest imbalance here is how close the defenders' respawn is to the flagroom, with zero setbacks.
ps- there no mass warp after the flag changes hands. intentional or glitch?