Kimberly, I was a GC for 15 years, licensing for a GC is at the municipality level in Colorado, meaning the city, if outside the city, the county. Lakewood is in Jefferson county but has its own building department, the Jefferson County Building dept would be if the address is outside the city limits of Lakewood, if it is in the city limits you go to the Lakewood building dept. As a GC, I would call the building dept I suspected the property was in and you give the building dept the address to verify, sometimes they would tell you it's not in the municipality city limits and tell you which building dept to got to. This is the first step in your process so you are talking to the right building dept, because they all are different, have different requirements and have adopted different local rules in addition to the standard code.
"Taking out a wall" may or may not require a permit. Any load-bearing wall will certainly require one, will sometimes require an engineer report and sometimes require your GC to have a more difficult to obtain contractor's license as they are sometimes tiered. Sometimes a municipality will require a permit just for installing drywall, some do not. Inside the city of Lakewood the restrictions and requirements will be more restrictive, outside Lakewood but in Jefferson County the requirements will be more lax. Jeffco building dept is one of the easiest and least restrictive building departments to work with, Lakewood is fine but no where near as simple as Jeffco.
As you can see the keywords to all this is 'sometimes you don't know until you #1 find correct building dept, #2 after you know which one call the building dept and ask. Typically inspectors are available for 'consultations' in the morning before they leave for their inspections and sometimes in the late afternoon when they return. Typically they are very receptive and happy to answer your questions.
-Find the right building dept
-Call them and find out when the framing inspector is available for a phone call
-Call at that time, if you don't get ahold of them, leave a message and be available, they return phone calls
For the rest of your questions - start with the right building depts website, they typically will have information online about what work does and does not require a permit.
How long will all this take? It used to be just a matter of days, with Covid that's out the window, but probably now no more than a matter of weeks not months.
Whether you use a local or out of state GC it doesn't matter, once he is licensed here he is just as local as anyone else.
One thing though if you think this out of state GC is so great, one of the proofs of that would be him/her being able to navigate all this I told you. If they are experienced with permits they should be able to figure out everything I told you and you should not be doing this leg work for them.
By-the-way - replacing a bathtub is not going to be considered 'cosmetic' anywhere with the exception of being way out and rural.