All good advice.
I would highly recommend you ask all those questions before choosing which department you wish to go to work for. Most will be happy to share the path to a SWAT type assignment.
It is an expense to the departments and liability not to have the most experienced, physically fit, stable and predictable personnel assigned to such duties.
You must expect to have 3 - 5 years experience to begin the process, desire plus peer and supervisor recommendations will be part of the process.
Plan on being married to a pager...as it happens when you least expect it.
Some Depts. offer bonus pay for such specialized assignments...many don't.
Some smaller departments have officers from surrounding departments who make up the SWAT type team.
Don't be too vocal or talk too much about SWAT as a newbie...learn the trade then the specialty.....a successful SWAT operation is one where NOBODY gets hurt....Civilians, Cops or bad guys !
Even in big cities where it is a full time job...there can be a burn out factor.
On those teams, when not training you are usually service high risk search or arrest warrants...never a dull day.
Hours and hours of boredom....shattered by seconds of shear terror......manager terror as you are equipped, been trained and are closely supervised and directed.
Good luck in your pursuit !