Hello Ma Lowe.
Oh, please don't be put off - keeping chooks is hugely rewarding and they are much more entertaining than rabbits! Once they get to know you, they are so affectionate.
Most of your negatives are easily dealt with:
1. You can get an automatic door opener, so that the chooks can be let out at the crack of dawn with you having to get out of bed. I don't have one as I have a three year old whose preferred time of wakening is usually c. 5.30am so don't need one but I am sure someone on here can tell you more about them.
2. Chicken poo isn't offensive as some. If you have cats or dogs then chicken poo is nothing by comparison. It barely smells and is (mostly) easily picked up. If you are going to have an every day clean-up, it should only take ten minutes or so (assuming you're not taking on hundreds of hens).
3. Red mite happens, like cat or dog fleas, although some never experience it. However, if you do get red mite, there are lots of people on here who can help.
4. Keep your chicken feed in rodent-proof containers so they won't be tempted!
5. We have a small garden but don't care about it much
Yes, they can trash the garden but there are ways of keeping them off your prize veggies (sure there are some threads on here about it - as I remember, those little short wire fences are enough) or you can build a big enough run so they don't need to be out free-ranging (again, there are guidelines on here somewhere as to recommended size).
Honestly, they are great fun and it's lovely to sit out and watch them mooching about. And there is the happy side effect of a few eggs - plus knowing that the girls that laid them were happy hens. It does take a bit of work initially, getting everything set up and getting the girls settled in but, once you have, you won't regret it!