I would look again at trying to sell rather than go in to long term letting at the moment.
A letting agent should collect the rent for you, and chase for any late payments, but realistically they soon revert back to the property owner to handle any serious arrears e.g. no payment for a couple months or so. Insurance policy might be a good idea, but still does not deal with a bad tenant you cannot easily move out.
Agents vary in how effective they are at actually managing the property, as others have said the tradesmen they use are usually unsupervised and most of the jobs that have been done for us under this arrangement have been mediocre at top dollar price. It is really worth hunting around for an experienced agent. Steer clear of any that puts a school leaver or other inexperienced person in charge of maintenance, collections, or any part of the transaction with the tenant really. This side of the work needs experience and a professional approach.
Likewise, at end of tenancy: An experienced agent, with a serious approach, is your best bet for getting compensation/deposit retention for any damage sorted out with your tenant.
There are also onerous (potentially expensive) responsibilities on landlords for health and safety, especially fire safety. It’s right and proper that all rented places should be safe, but the regulations often exceed the type of safety measures you would have in your own home, so there might be up front costs to put them in. Also, anything in the house which is not totally 100% fine and working (sometimes as a homeowner we might readily live with e.g. a cupboard door that sticks, a lock that needs a ‘knack’ to open it, a tap that drips unless you know to turn it off thoroughly etc) will need fixing or replacing before you let, otherwise you will get complaints, broken items, or expensive repairs.
Who would be a landlord these days!? 🤪