I'm under the impression that by "it's not worth of my time", you actually mean "I don't like sysadmin" :)

Ha. Well, it's more that there are things I can justify charging for and things I cannot. Standing up a sub par solution for a larger investment of time doesn't make a ton of fiscal sense to myself or my clients.

Yeah indeed, for contract customers, better go with something you're confident everybody will already know, since other people will have to manage it when you won't be there anymore.

In a previous startup I was CTO and founder for, I used a gentoo and managed everything possible by myself. This was not especially costly in time because I was already used to it and efficient, and we managed that way to stay for 3 years with 70€/mo in infrastructure cost. This has its advantages too :)

Setting iptables is not absolutely necessary since DO offers a built-in firewall.