The temp deal is of no concern, yeast would actually like to have 80-100f for optimal growth which is what you are seeking with a starter. So room temp is perfect, during the actual ferment is where you are concerned about temp because if you ever taste the wort decanted from a room temp or higher starter you will see why temp makes a diff for the “true” wort you will drink.
The 650ml is a number somebody dreamed up in their sleep. I have no idea why they quote that method(well sold with a 1000ml flask that’s all you can make really(650-800ml maybe) if that’s what they are speaking to here in said instructions) But ultimately you would rather make 1000ml or bigger depending on the beer gravity. Now if using a stir plate this volume needed game changes considerably.
If no one has introduced you to mrmalty.com, check it out…Many good facts to gather about starters and the yeast pitching rate calculator is what you want to seek out.
Also while I’m at it a starter wort calculator: http://brew.stderr.net/starter_wort_calc.html
At this time you have yeast that was produced on/around Feb 8th 2012. So the viability is 16% which isn’t bad, but you need a starter size geared to make up this deficiency now. So 650ml wort added to a 16b cell count = 57B cells much too low for even a 2% ABV beer. The way to increase the count further is to employ a second stage step up. I will just use 1.055 as a typical brown ale SG just for demonstration. 1.055SG will require an optimal cell count of 202B for rounded performance.
57B cells added to 2L will hit 192B which is much closer to the mark and in range.
A simple 1 gallon glass jar with a large cotton ball for stopper or tinfoil covering the opening is all you need for now. 2.2L second stage will hit 202B cells, but anything approaching 2L is desired right now.
The best way to add started yeast to the “true” wort is to first decant the spent wort. This is also done with staged starters 1,2,3 step etc… You briefly put the vessel in cold storage a few minutes (10-30) and this effectively crashes the yeast to the bottom, sanitize lip of vessel, then pour off the spent wort leaving just enough to swirl up just the slurry left on the bottom and pitch.
Now with doing steps you would just sanitize before opening the starter vessel, decant, add new sterile wort(sanitize all transfer funnels/tools)or simply “pitch” the slurry into the new sterile wort vessel, make sure to sanitize the lip & stopper of choice again(sanitize: flame/starsan sprayer etc…) and replace. It cannot be repeated enough, but sanitize everything in sight that is involved in yeast handling. Repeat or pitch as nessecary.