I am planning to start a Roth IRA, because I will probably be in the phase out income bracket of the traditional IRA in three years. Feel free to comment if you think it would be worth doing traditional for 3 years and then transferring
I'll take this part of the question since no one else is. Generally for Mustachians, it's more optimal to use tax-deferred ("traditional") vehicles rather than Roth vehicles. So if you have the opportunity to contribute to a Traditional IRA, it might be worth it. Be aware that the phase-out income level increases each year with inflation, so depending on how your salary-increases relate to the inflation level, you might have even more than 3 years in which you can contribute to a Traditional IRA. And it doesn't really matter if it's 1 year or 3 years or 10 years that you have the opportunity available to you. You never have to "transfer" anything from a Traditional to a Roth, you just stop contributing to the Traditional and contribute to the Roth instead.
The only reasons I can think of to not do a Traditional: 1) if your salary is increasing so quickly that you'll soon blow by the Roth income phase-out as well, and will want to do "Backdoor Roth" contributions; in that case it helps if you have no money in a Traditional IRA (given how high the Roth limit is, this scenario seems unlikely). 2) Your income is currently so low that your marginal tax rate is 15% or lower.