1- Is it useful for players if they have the ability to sacrifice heroes they dont need in exchange for exp , diamonds , or even other heroes shards ? ( this is my suggestion , and my own opinion is yes ) .
No, changing hero cards to other resources would be pretty much "broken" as then it would be possible to reliably farm diamonds or "rare" hero shards by buying a ton of gold chests while you keep "sacrificing" all the 1 star hero cards.
2- What about having a survival mode in the game ?
We already have CoF, which is the most tedious thing in the game because at higher levels you're basicly fighting 15 exact same teams... there are gorams, sylphis, orkons, vulkos everywhere.
What the game could use to make CoF better is a better loot table and a standard "sweep" option.
3- Do you think the game should make championships (even bigger than the epic arena , something like wars between players in different servers) ?
No, different servers have different levels, even if there would be a level cap or a battle rating there would be no way to balance this and only the bigggest of whales would be actually able to compete for the top prices. The game needs slightly better balancing the gap between "whales" and lesser spenders. An event like this is counter productive.
-Do you agree that there are some overpowered heroes that need to be fixed such as zem , hurok , or even rayman , etc.. , and some others are below average ??
Yes and No, game breaking abilities should be nerfed, like Vulko and Desmond's damage output in order to promote diversive strategies. However CS heroes and Box event heroes should be a decent chunk better then any free hero in the game. People are spending diamonds/$$ money for them and I do believe that people who are paying should have some advantages, including having access to stronger heroes.
Zem is not overpowered, Hurok was overpowered and Rayman... well I guess that is what you get for 150 dollars...
5- Do you agree that the company of this game should consider lowering the price of upgrading heroes to 7 stars ?
Yes,prices in general are rather high, especially if you play in europe then my 99 dollars is like 115 euros... which is completely retarded. However what must be done is make the "rare" SS more readily available for f2p and people who dont spend huge amounts of money.
6- How about making new stages , adding new features , special weapons ??
No, let them fix the old content first, we need a complete rebalancing of the normal and heroic stages and their rewards. All the currently released features are intended for players level 100, which is nice but a very bad choise. We need decent evens at a regular interval where all people can participate on their own level.
Events like tower of kings once every 3 months, Return of the ancients once every 3 months.
With regards to special weapons... NO, we already have an academy and awakenings and we recently got runes, I personally think that is more then enough.