What should I do and how can y'all help?

I suggest seeking counsel now. Much is detail dependent in these situations

What is the legality behind L/E being hired as security and conducting searches on behalf of a business and verbal commands/srch

Well there is no criminal charge mentioned so there is no constitutional violation regarding search and seizure. As for him being rude... that is...

How can I get a no fault divorce

For a no fault divorce you and your ex must agree upon all aspects. Otherwise you must have a fault based divorced

How can I keep her from selling my family's land and is there a way for me to buy her out of the property if at all possible.

Has any of these estates been probated? I am guessing not. Please seek counsel to be able to determine heirs and then there can be a division or...

How do I find out my options to split custody

You are in a difficult legal predicament. As the husband he will be assumed to be the father and will be named the legal father, You will have to...

How do file for custody & put a hold on that check to get what he owes me

you nee to file for modification seek counsel

Can I get him for abandonment and adultery? Will I be able to get alimony?

Abandonment requires a year. Adultery is an option. Seek counsel now

She cannot be arrested as a run away at 18

What do I need to make sure to attain in the agreement so that I do not lose out on access to my son?

Do not sign anything without reviewing matters with a local attorney. Have an attorney prepare the paperwork

Can I get forced by my parents to get married with my ex, I'm 16 and she's 15.

You cannot be forced to marry. Seek counsel NOW