Instead of saying the competition 'sucks' I would instead explain why my product is superior to their. Accentuate the positives of your product, not the negatives of the competition (which, if they have already used the competitions they already know well enough).
As for #5, yes for a Facebook group it would need to be popular. But with twitter you can attach relevant hashtags to your post, resulting in it showing up in searches as well as for those that follow you.
As for #5, yes for a Facebook group it would need to be popular. But with twitter you can attach relevant hashtags to your post, resulting in it showing up in searches as well as for those that follow you.