Personally, I would mold this deck by including more cards with the storm mechanic, fast mana, and things like Thousand-Year Storm to get even more value out of Kalamax
The fact that this creature is legendary means that there is a possibility for a themed Commander deck
The first damage step is for creatures with first or double strike and the second is for every other creature without those keywords
Youve probably got a few that came straight to mind if youve been collecting for a while or buying cheap bulk cards at every opportunity
You control the damage, not them
Make use of the HyperGeometric calculator, and if youre building your deck list online, some websites such as Moxfield provide great stats such as colour breakdown, costing curve etc