Make the game more rewarding to skilled players
I think the game should be way, way more rewarding to skilled players. Right now a piss poor team can hold out against a fantastic team. A poorly played hero stands a chance against a well played hero. And each fight/kill does not feel like it impacts the game very much. Here are my ideas to improve such:
1. Improve the interface. Right now if I'm a general, I don't know what what troops I have selected, if they're fighting, if there others I'm not properly controlling, nor how good the troops actually are. For assassins and generals, I sometimes have difficulties telling who I'm attacking and I never know if they're casting a spell or about to cast a spell.
2. Put in more timing/skill based spells in the game. After #1 is accomplished, this gives players more opportunities to really do things with their troops like control who their clerics heal (if they so desire). Spell interrupts will be drastically more effective if you can see that someone is casting a spell. I would love to see a hero or two get an ability that intantly breaks him from stuns, and then another ability that breaks a character loose from all snaring effects for a period of time. You can give someone a spell reflection ability that will reflect all spells cast on the hero for 1 second. You could bring in heals over time and then bring in the ability to steal those heals.
3. Speed up games, slow down heroes. In my personal opinion a game between 2 average skilled teams should last ~20-25 minutes and result in most heroes being around level 15. A game where advanced players beat down on new players should only last 10-15 minutes. Only rarely should a game become a drawn out back and forth fight when both teams truly are equally matched and keep it going back and forth. Why? Because otherwise every game feels the same. To do this, I suggest having movement imparing abilities completely remove the effects from any boots and actually reduce the base movement speed of that hero. Also move the healing crystal further back. To keep this from becoming frustrating in it's own right make scrolls of teleportation cheap, but have a 5 second casting time. Also town down un-upgraded buildings drastically. A low level hero left unchecked should be able to kill one of the front line buildings in under 30 seconds using no items.
4. At later levels, deaths should have real dire consequences. I'm thinking over 30 seconds for a level 17 hero and over a minute for a level 25 hero. Someone dieing should really help sway a battle.
5. Tone down passive gold collection that is not from flags. Killing heroes/units and capturing flags should be practically the only way to get gold. This once again helps set apart the teams who are good and those that are bad. EDIT: to clarify, I'm ok with flags giving descent gold as well because you have to fight over those flags. The amount of gold you just get from having a citadel, especially after its been upgraded is my main complaint.