Alimony & child support

Question #1: Is alimony and child support agreed during the mediation 100% legally enforceable? Any loopholes or caveats for guys to get away from paying what is agreed during mediation? Question #2: After 20 years of marriage and two kids (11 & 18) and husband making good money and prospects to make even more in future - what is advisable for women - should she agree to sign divorce papers with a good settlement offer or keep lingering the divorce? Any other related info shall be highly appreciable.