1. Using IEOs instead of ICOs, we are adding a 3rd party than can control what we buy. This is in contradiction with the main purpose of cryotocurrencies which is centralization
4. Exchanges might get money and do not pay attention to healthy of the project like what they do for listing the tokens
I don't think your opinion 1 is correct. The exchange' IEOs do not have smart contracts to check how much money has been transfered into it, all paramater are provide from exchange.
Regarding opinion 4, ít's true with almost projects so far, the exchange is just a listing and allows you trading, they have no right to interfere in the project.