Re: termite damage
First, you need to make sure that the pests are gone or you'll be right back at this in a short period of time. A pest company will be the easiest means of eradication. I would choose one that does repair work as well because in my experience they are more honest about the problem and aren't just trying to sell their chemical application and service contracts.
Second, the extent of the damage needs to be assessed, along with your ability to do the work. It's going to be faster and easier if you hire the work done, however from your description it sounds like something that a person with good home repair abilities could handle with relative ease.
Third, acoustic texture on ceilings can be sc****d off. It's a messy job, but not nearly as messy nor hard as resheetrocking. All you have to do is lightly wet the texture and it will soften and sc**** right off. If it's been painted, sc**** the texture a little first to knock the tops off the bumps so that moisture can penetrate. I use a clean, dedicated (water only ) pump sprayer filled with water to mist the texture and a combination of a 6" drywall knife and a long handled floor sc****r like this. I also tend to sharpen the floor sc****r with a belt sander to help get under the texture.
Sprayers - half gallon and one gallon size.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!