Looks like a really tasty grain bill there. Very similar to an alt recipe I will be brewing in a couple of days.
On the starter, you won't see much activity on a stir plate, the constant agitation will keep the krausen knocked down. If you stop the stir plate for a hour or two, you can see whether the size of the yeast layer has increased. That said, you won't see much growth in only a 1 liter starter. You really need at least 2 liters of starter for an ale and a minimum of 3 or 4 liters for a lager. With the low fermentation temperatures you should be using with that yeast, you would be looking at a 3 or 4 day lag time before any visible fermentation from just a 1 liter starter. You should really take a look at the pitching calculator on www.mrmalty.com
to determine just how much yeast you will need. Before getting a huge erlenmeyer flask, I used to use a one gallon glass wine jug on top of my stir plate for doing big starters. For the 810 yeast, you should aim for about 55° rather than 60° for a fermentation temperature.
On the protein rest, it isn't at all necessary to do one at all with most modern malts. You pretty much have to special order the undermodified malts that require such a rest. If you were doing a recipe with something like 40% wheat malt, then you might need a protein rest. In the 100+ all grain batches I have done, I have not found a need for one yet.
As far as when to panic goes, if you plan to only pitch a 1 liter starter in this, it's time to panic now. As mentioned above, it won't start in a reasonable amount of time. Assuming your sanitation is good and you don't get an infection during the lage time, you will still get a bunch of off flavors.
When greatly underpitching, which is what you would be doing, the yeast will spend the first several days reproducing rather than converting sugars to alcohol. A high rate of reproduction will produce great amounts of esters that will adversely affect the flavor of the finished beer. This is the reason for needing big starters. Such underpitching greatly stresses the yeast, as such the yeast may quit working before all the fermentable sugars are consumed, leaving you with an unacceptably high final gravity.
If you are unable to get a bigger starter built, I highly recommend planning to pitch a good dry yeast right at the start instead. Nottingham fermented at a low temperature (55°-60°) will give you a nice "pseudo lager" character. US-56 for an APA, or S-04 for a slightly fruitier english bitter (if you do an english dry hop).
I hope I haven't discouraged you with the news about the yeast. If you have a large jar or jug, put a couple liters of starter wort in that and pitch the yeast you already have going in there. It probably won't work on your stir plate, so put it some place that you will pass by frequently so you can give it a shake everytime you are in reach of it. That should give you sufficient yeast count.
Bugeater Brewing Company