Second time around!!

1) My main stalk was really thin/small my first time how should i improve that other than using a fan?? Or is that the only way?
2) Do "sweetening" products really work??
3) If your all organic, do you have to "flush" the plant before curing?

4) Is a 150 Watt HPS enough for one plant?
AND if i bought some seed would it really be worth it??

1. Stronger fan would be best, but you can break the inside fibers of the stem and it will repair itself much thicker then before.
2. Never tried them myself but from what I hear most often then not is "no".
3. Not really sure what you mean on this, all organic is referring to the soil and nutes used so not sure how a flush would be required? Or am I wrong here?
4. Yes, and probably but not really required for first grow. Mainly just help in knowing sex before flowering.

3) Iv seen in magazines and online that if you use chemicals in your plant that 10-14 days before your pull it you should water it with just water...IDK its what i read...

So a 150 Watt is OK?!?
AND is the product from "good" seeds allot better than that of "bag" seeds?