Talon...Riotu...pls...(Mana and Cooldown problem)

I'm a bit new to league, only started playing in the mere beginning of 2015. I'm new I don't use that many champs. I currently main three my best main being Talon . Even though he is my best champ I still find him in cringing moments at times. After I defeat my opponent in mid-lane I always use up so much mana. Sometimes I forget about this while roaming to my bot lane hoping to help then realizing I'm out of mana when I meet the enemy adc and their support low. I engage them with the intention of getting a double kill through using my ult. Then I realize i don't have mana and just get killed by them. What I'm trying to suggest here is Talon doesn't need mana. In fact( well at least to me) mana plays as a GREAT hindrance to Talon. Champs similar to Talon such as Katrina, Zed and Akali are also assassins who play similarly to talon yet don't have that mana bar hindrance. They could use their moves as long as they want without worry about heading back to the nexus to mana recharge or buying mana regen items. Mana isn't the only problem Talon has. He has some really slow cooldowns that should be reduced. I have some cooldowns runes - Greater Quintessence and some minor greater Glyphs. In game ( if I am doing well) I buy late game items with decent cool down reductions like Yommu's ghost and Black cleaver and still find myself missing an opportunity like a low hp Les sin running away after I killed his adc. Many times I get yelled at for missing stuff like this by my teammates. I always resort to explaining to my teammates my 7 sec cool down on my cut throat (e). I must admit, Talon's ult is has a great cooldown, actually all his moves have great cooldowns its just his E which is also happens to be one of the most important spells for him has an undesirable . Shortening a bit to 4 or 5 secs would really help. The cooldowns are a huge problem but not as sever as Talon have a mana bar. So pleas Riot and other follow player read this and give me a suggestion. Please riot, remove Talon's mana bar at least.