normal tackling.
With 4-1-4-1 I would use red arrows to my ML-MR (unless I want to keep a good result).
With 4-5-1 V, no arrows (unless you want to score).
counter yes
The most important is to stay in defense/counter mentality even if he scores a goal.
Don't go to attack as you have a second round.
Only in your 2nd leg, if you see you're loosing qualf., go to attack.