I have a bit offtopic questions about forking ethereum and i think this is the best community to seek asnwers
After forking ethereum, what kind of servers do i need to actually deploy it, will AWS work?
How can i modify/patch it later? (How can i change already deployed blockchain - what tools do i need. For testing purposes i know ganache and truffle)
Can i reserve some coins on specific address before deploying it
After forking ethereum, what kind of servers do i need to actually deploy it, will AWS work?
it depends on your consensus of the new chain, such as the test chain Kovan, it is a Proof of Authority (PoA) publicly accessible blockchain for Ethereum, so for Kovan, it does matter, you can run the node on AWS, but for the chains of POW, you had better use a miner.
How can i modify/patch it later?
If you want to update the chain later, you can make some hard forks, such as the Byzantium for the ethereum, but this needs all nodes upgrade the node.
Can i reserve some coins on specific address before deploying it
Yes, you can, but you need to add the initial distributions in the proof of consensus, so every node will agree with it.