I currently have Lydia as my companion. So far, she's been pretty decent. However, as I've been encountering more and more companion options, I'd like to give others a shot.
My question/s: Can you "dismiss" your current companion without losing him/her forever? I have noticed one of the dialogue options with Lydia is "we must part ways" or something to that affect. What does that mean exactly? Does she leave for good or does she just go to my home in Whiterun?
So can you try different companions and switch back if you are not happy with your current choice? I'm afraid of getting rid of Lydia and losing her for good..lol.
Oh and if I pay for a companion such as Marcurio, does he stay with me indefinetly until i dimiss him or is he "hired" for a set period of time only?

Thanks in advance. Any help is greatly appreciated!

she goes back to your home in whiterun or she goes to dragonsreach

I made Lydia a set of dwarven plate, does she keep it after I dismiss her or will she "reset" to her old gear when/if I meet her again?