We have gone down the same road discussing the same options as you.
Here are my thoughts on the conclusion we came to.
We rent out 14 acres to a farmer for suckler cows from May to November. The rent is not a lot. I doubt we could make a living by keeping our own livestock on that 14 acres ......although we do keep our own. More of a hobby interest though. Certainly do not make enough to give up work!!
We have looked into keeping liveries, as we already have a lot of ponies ourselves. But if you take on more than three, the council tax you on the stables, so you need to charge bigger rents. A lot of livery yards round here are struggling, clients are having to sell their horses due to the credit crunch. So, we have held back on that idea for now.
When you say working liveries, do you mean you will use them as a riding school horse, or trekking horse? We looked at the trekking centre idea, with bed and breakfast for the owners. Again, the issue of credit crunch came to the fore, and we did wonder about it being seasonal. I know people ride all year, but up here, we have severe winters, and cannot see people wanting to ride over our moors in a blizzard!!
We have a mortgage, and I would dearly love one of the above ideas to work for us, to help pay it. At the moment my OH works full time and I am part time.
We would like nothing better that to be able to give up work and live off our land, but at the moment that does not seem possible.
I wish you luck with your venture, and hope it works for you!!