"Is it possible to also rollover to 401k the earnings in the traditional IRA as well?"
Yes. The only requirement is that you roll over to the 401(k) no part of your basis in nondeductible traditional IRA contributions. In other words, upon making the distribution from your IRA for the rollover to the 401(k), the balance in your traditional IRAs must be at least as much as your basis in nondeductible traditional IRA contributions.
There is no such thing as converting to Roth for a particular year, only converting to Roth in a particular year. The conversion is reportable on the tax return for the year in which the distribution from the traditional IRA occurs.
