How big a role does past experience play when managing?

If managing a medium to big club, what role does your past experience play in all aspects?

Say you are managing Liverpool, Utd or Spurs with professional footballer as opposed to international football. Is the difference negligible or what?

That's a very good question I'm very curious about too

maybe i just set to automatic instead, then presumably it'll give me the normal rep associated with the club

In itself, none. However, your reputation (the starting point for which is decided by your past experience) affects the amount of respect you are given as a manager by the players, and probably the board.

I will matter mostly when applying for (or being offered) a job at a bigger team, or for managing a country. The bigger your reputation, the bigger the chance you're given the job.

Ok, so if i am an ex-international i will be given more respect by, say, Van de vaart or Gerrard, than if i am just an ex-pro?

It makes quite a bit of difference. Both how much your players respect you, and whether players you want to sign will come.

Start as Semi-Pro in Brazil and you can only get a lower league job, start as international footballer and you can get a job at Santos FC and the likes.

If a player or staff knows who you are, of course they will want to join you - or at least it is a bigger chance that they will consider joining.