You may be one of the first to file when it opens tomorrow. Congrats.
$0.22 income does not need reporting since you round on your tax forms and that rounds down to $0.
You are correct on your 401k contributions. Since they are included in your w2, the irs makes it easy with no other form needed - as long as you didn't make any withdrawal or have any unpaid loans that are now income.
You do not need to wait on your Roth IRA contribution forms. Technically, since you don't submit supporting docs other your tax forms, you don't need to wait on anything but you better be darn sure all of your numbers are right and that you didn't forget anything. I personally find it better to wait a few weeks for docs than to file an amended return. Check your provider's website since you can usually find tax docs there a few days to a week ahead of receiving them in the mail.
Brother - now this is a sticky one. I would highly recommend finding and following the rule for claiming a dependent to the letter of the law. You do know the 50+% rule but you need to know % of what. You also need to make sure that no one else claims him as a dependent.
As to what other forms you may need, that is very hard to say since it is sooooooo very subjective based on you actions throughout 2015. Look at page 1 and 2 of a blank 1040 and you will know right away if you are missing anything big. Here is my general list:
Income: W-2s, interest, dividends, capital gains, rental property (one via schedule E and one via a K1), previous year state tax refund
Expenses: hsa contributions, ira contributions, capital losses, mortgages interest, teacher expenses, donations, 529 plan constitutions,property taxes, tax prep expense (software).
We don't have tuition expenses, student loan interest, and childcare expense anymore but they are common deductions for many people.