1. What is the best exchange to buy ICOS?
not a good idea to invest in any ICO, you are helping this method of scam to grow when doing so.
but since you asked, you have to check and see which exchange is offering them sometimes it is Yobit, sometimes Liqui, others are also listing. choose one and go there.
2. What is the best "sub-penny"(below one cent) coin to buy right now and hold for the long term (3-5 years)
bad idea also. because an altcoin that has such a low price is low for a reason. it did not go down there by accident! it is there because of flaws in its project or in economical aspects of it for example because of a large amount of supply (example Dogecoin) and in long term these coins will only go down.
3. What would you choose for the long term? Litecoin or Ethereum Classic?
again not a good idea to go in long term in any altcoins.
but these two options both have good chances. mostly LTC because it has been around for years and it has been above $3-4 for the most part of it. and also it has a good developers team.
4. In what coins are the most banks involved?
Ripple first, then Ethereum because of its (in the shadows) investors.