So I managed to create ICO on ropsten testnet. But I have few difficulties
1) I want to create a webpage where users can buy my ICO. But how to do this without using MetaMask plugin? I want such that user can send me Paypal, Visa, ETH in exchange for ICO Tokens.
2) If I want to launch my ICO on live server, do I need to create my own Node or just use Ethereum mainnet? What are the benefits of using own node vs using ethereum main net or vice versa?
Really depends on how you want to implement your solution. How most ICOs does this is they let people give them money and pay upfront. So for this you can use API from etherscan to get Ethereum transactions, integrate Paypal and Visa. Then you will want to store somewhere in the database the address investors want to receive tokens in as well as how many tokens they will recieve. After the end of token sale you can simply take that data (can write simple script) to send out the tokens.
With node you don't have to trust others but you trust the data you have with your own node. Honestly if you are looking to do any more advanced features with the network I would advise you to use your node because you can do many things with it.