Yeast starter questions for lager beer

I'm going to make my first lager, and have a couple of questions about the yeast starter.

What temp should I keep the yeast starter at? I'm going to be using WLP833.

I am going to do a 1/2 gallon yeast starter, how many days prior to brewing should I make the starter?

There are a few ways you can do it, but personally I like to do my starters around my fermentation temperature...around 50. The lager yeast is much slower so what I like to do is prepare my starter about 4 days in advance so that it can ferment completely, then crash it for a day in the fridge to let it settle out. Then decant on brew day leaving about an inch or wort, give it a good swirl to re-suspend the yeast and pitch. Decanting is not necessary, especially if you do your starter at a low temp. If you do it at a higher temp, it will ferment quicker but you may have some off flavors, so I would definitely decant.

I start about a week in advance. I ferment the starter at room temperature, after all I"m growing yeast not making a lager, and then when it's fermented out I put it in the fridge for a couple of days. It sometimes days two days or longer for the yeast to fall out completely out of the starter, as lager yeast will not always readily flocculate in temperatures in the 40s so it takes a while.

On brewday, I decant the spent wort and allow the yeast to warm up to about 46-48 degrees and chill my wort to 50 degrees and pitch it and keep it at 50 degrees.