If this forum were about movie, games or comic, your idea wouldn't be bad. But otherwise, i don't see any strong reason to make your idea into reality.
( for example, forum member with IT higher education will almost always be step higher than any other member with just home made IT knowledge
That's obvious, after all they're likely to spend more money and time towards knowledge and experience they obtain.
so how can home educated forum member can give merits in IT field to member with university education ).
I fail to see what stop any member to give merit to member with formal education.
Spammers and trash posters are present in all forums, also here - merit system can not help, if the member want to spam & trash, he/she will do it.
That's true. But if they don't get paid or paid less for spamming, there's less reason to spam.