I've got to say i've been to EMA when theres been racing on at Donnington and the road is a nightmare. I can't even begin to imagine what it will be like when the F1 is hosted there!
Regarding security - Better to be over cautious than under cautious. Theres probably multiple reasons as to why they are strict even with air crew. I've flown planes into airfields and then gone through security but it doesnt really bother me. I normally just hold a general conversation with them which makes the process nicer and less stressful for all involved. They're doing their job and its all for the safety of everyone involved.