RELAX
I think I agree with everything I read here but I'll emphasise what Flap 5 said...don't get uptight (difficult under the circumstances)
Try to relax and make fairly slow and slight control imputs.
I think you'll find that whoever's looking at you will be looking more closely at your character (easy going, good CRM, sensible etc) rather than worry about a few handling mistakes on an aircraft you've never flown. If you approach the handling with a common sense approach ie slow deliberate movements...you'll probably be forgiven for any minor errors you make.
Some simulators are bastards to fly by comparison to the real thing, so don't get too upset if you feel your control movements appearing to result in slight "jerkiness".
This often makes life difficult during the 500 feet on an ILS.
If you fly a reasonably good approach to about 200-300 feet above decision height, and things are starting to go a bit wrong for you at that stage, just make ONE last correction and then hold your heading.
If it really goes wrong for you at that stage, don't try to be clever by pressing on. Show them you're sensible and go-around.
They'll want to see a sensible character who they can train to fly their aeroplane. They don't want a whizz kid with no common sense.
Good Luck..and ENJOY it !