Even if this post is a bit old, I still want to comment on SAM-e:
200mg is way too little for an undermethylator (you will probably not notice anything). If you do not notice any effect after taking 800mg for one week, you should increase to 1200mg, etc. 1600mg is also OK for undermethylators, but the tolerated dose is trial and error (introduce carefully, and wait one week until the next increase).
It will take months for significant improvement. Also, consider other nutrients for undermethylators helping the methylation/methionine cycle, both for keeping the natural production of SAM-e and conversion from Homocysteine in order, etc.
I know this topic does not cover longevity, but keeping in mind that this is the primary purpose of this site: Undermethylation is increasing chances of developing cancer and also early aging. If you want to live "forever," you do not want to be severely undermethylated because most people develop cancer at one point or another (and you do not want it to be too soon). I can post references/links to scientific evidence later. Likewise, overmethylation often leads to high Homocysteine which increases the risk of cardiovascular diseases. You can reduce risks with the appropriate supplementation.