I really really enjoy childminding. Yes, there are days when the baby won't settle and seems to have forgotten the "off" button, the toddler has drawn all over the walls and forgotten that he's toilet-trained, and the afterschool child has flooded the loo and shaved the cat. But, for me, there are far more "good" days - sitting in the middle of a park having a picnic, walking in the woods and looking for butterflies, making snowmen in the garden, socialising with friends at a toddler group, and having that choice over what I can or want to do - and then being paid for it (and giving the children back at the end of the day!!) I love it!! And I get to do painting and glueing!!
Paperwork is a pain for all of us. OFSTED seem to demand more and more from us, but you won't get kicked out if you haven't got something, you'll just get a reminder to sort it out. If doing your tax sounds horrendous, so get someone else to do it if you can (liked goosey's link). You don't have to keep heavy-duty accounts, just a weekly record of your expenses. The NCMA have helpful guidelines on what you can record as expenses.
Don't take on too many children if it makes it too stressful, you don't have to work to full capacity. Or maybe do it part-time, or just have schoolchildren.
Lots of minders do the job whilst their own children are little, and stop when they go to school, so don't feel guilty about not committing to doing the next 20 years!
However, if you can't deal with looking after other people's children and you're not enjoying it, then I would say don't do it.