What's a good product for customer support?

I'd suggest trying Freshdesk. It covers the 7 asks that you have and is priced quite affordably. It comes with a 30 day trial as well. Give it a spin.

HelpScout has a ton of options for customer support that fits the criteria you're looking for.

Faasthelp has all the features you are looking for and for an affordable price, simple, easy customer support engagement software Simple live chat, Easy helpdesk ticketing system where you can add any number of agents with no additional costs, a knowledge base where you can add any number of questions and also an additional feature of Knowledge base questions is that you can add visuals, screenshots to the questions for better understanding.

Freshchat is a powerful, full-featured modern messaging software for sales and customer engagement. Made for web and mobile chat. Powerful Intercom-alternative.

Deskun fits almost every criterion from your list. It's a simple and very affordable tool.

Helprace is a easy-to-use help desk with all the features you listed. It's also a knowledge base, community, and feedback management system. All cleanly integrated with one another. You can disable things you don't need and only pay for what you use.