1- It takes so long because there’s a lot goes into it, the different stages of pre-application bits (tests to be done, personal statements to read and sift etc), everybody who is involved in the recruitment process also has their own full time jobs, they aren’t just sat there 9-5 every day reading applications. Also, the application stage has to be “open” for a set amount of time, which could be say 3 weeks, so if you spot the advert and put your application in one day 1 then you are going to feel like you’ve been waiting a long time because it’s going to be 3 weeks before the closing date, and they are not looked at before then. Once closed all of the assessing & sifting has to be done to get the best candidates out of it, all of those involved have their own jobs, hence time. Then the interviews, again, people have to agree to be interviewers, have to carve time in their own work day to be able to do it. It takes time!
2- If the job has been advertised both externally and internally then there is nothing to say only internal candidates will get invited to interview. They want the best candidates, regardless of where from.
3- A high test result can be the difference between being put on a reserve list or not, if there is one, for the role you’ve applied for. But a high test result doesn’t mean you’ve got the job because actually every applicant could get a high result. If you are not offered the job but did score highly on tests & interview then there’s a chance you could be put on a reserve list for 12 months so that if any other vacancies come up in the next year you could be offered one.