The short answer? You find one reliable person who you like working with, then you delegate increasing portions of the work to them.

For example, I had a pretty good working relationship with my ex-freelancer for BCC bingo card content, but let's pretend that I was serious about never spending my time on that again. What I would do is a) grab all the docs I had written about the process, b) spit them into a Google doc document with headings like How To Find A New Freelancer, How To Make a CMS Account For A Freelancer, How To Pay Freelancers, Content Guidelines, etc and c) hand that off to the young lady in the Philippines who does utility VA stuff for me. Then, I'd have her hire a new freelancer and do one week of work with them, with instructions to email me at each step for review. I'd give feedback and update the docs where required. After she was capable of doing it without needing my supervision, I'd tell her "Great, it's yours now. Make it work and send me an email once every two weeks with what you did, what you're doing next, and anything you need from me. You have my email any time if there is a problem that you need an answer to. If resolving the problem would cost less than $100, pay money to solve it and just tack it onto the next regularly scheduled email. I trust your judgement."

n.b. That $100 idea is flagrantly stolen from Tim Ferris.

As for normal: if I work with three people, I expect one or two to be Too Flakey To Use Successfully. That's just a cost of doing business. This suggests a) getting out of the talent identification business, since either I suck or it is impossible to do well and b) hanging on to good people for dear life. I sent my BCC freelancer a Christmas bonus every year and thank you notes, and got ~3 years of mutually rewarding work out of her.

Regarding customer support: I do customer support myself. All of my CEO friends are trying to get me to stop, principally because they are all tired of hearing "Ooh ooh ooh guess what a customer just asked me about how I broke her blue Googles?"

If I were emotionally ready to stop, the first step would be writing a Google doc with instructions and four buckets of customer support inquiries, which represent ~80% of the emails I write. Each bucket would have a template email to go with it.

The instructions would be "Bucket the email and, if it is clearly in a bucket, reply with the template and $INSTRUCTION_FOR_MAIL_FILING. If not, leave for me to deal with by $INSTRUCTION_FOR_MAIL_FILING. If you're less than 90% sure, leave it for me."

Then we'd iterate on that. If they could handle bucketing, I'd move them up one step: here's my core principles for CS. I always want to make them happy, a refund is always an option, we never do custom dev under any circumstances. Here's four emails from customers which were not bucketed last month. Write responses to them like you think I would have written responses, then send those responses to me.

Then I'd say "OK, I like the content here, but I always start emails out with thanking the customer for emailing me. This email here said 'If you hadn't clicked' -- that phrasing is not acceptable, because it implies customer fault, and the customer is never at fault for a failure of our software to anticipate their needs. Otherwise, OK." Then I'd start them on live emails and review their progress. After that: "Congrats, you're now level 1 support. $INSTRUCTIONS_TO_FORWARD if you're totally bewildered by an email. Good luck."

As you go forward, document your processes. I cannot stress this enough. That way, when your current support gets married, stops responding to emails, or informs you that she has taken a job at a multinational and will no longer be freelancing, you can quickly get the new person up to speed. (Or, even better, your trusted lieutenant can quickly get the new person up to speed.)