Here’s my run down on how to fight the harrier. AV8B N/A Tips and tricks - Flight Sims - Mudspike Forums
If you want to keep things simple stay away from AUTO bombing, and just use CCIP.
Also since you have FC3, if you don’t mind being rather slow, the A-10A is a great bird, that most of us learned on what back in the LOMAC days (Lock on Modern Air Combat, was DCS predecessor). It is very forgiving, very durable, and carriers an insane amount of ordinance.