I am like you, in my 70's. I did not buy a tractor with a cab when I purchased my tractor 15 years ago. Now, I really wish I had a cab. But, I take care of 92 acres in East Texas with almost no trees. Sounds like you are in between the proverbial "rock and a hard place". A cab would be...
I've used a Stihl FS-90 for the last twenty years. It will handle anything you want to tackle. I don't like string trimmers, so I use the Stihl head that has plastic blades. Works great.
Now that I have a front end loader, I would never have a tractor without one. So many things they can be used for that you can't even think of right now.
I agree. Remedy is a good product for brush. It also works well on fresh cut tree stumps when mixed with a little diesel to prevent any regrowth from the stump.
I have and Oregon Scientific brand for my house. I don't like it. Very hard to reset the various inputs after changing the batteries. Usually takes me about an hour - all hit and miss.
If the bottom of the T-111 is within 8" of the ground, try to make is shorter. If not, water will wick up the wood and cause rot. Been there, done that. A good stain probably provides the best protection.