I'm planning on brewing my first wheat beer on Saturday to make a change from my usual hop-driven brews. I got "Clone Brews" for my birthday and the Paulaner looked like a good place to start. The recipe calls for 2400g malted wheat, 2200g Belgian pale malt and 113g dark Munich malt for a 19 litre brew length. My first question is can I substitute Pilsner malt for the pale? I have Weyermann's Bohemian Pilsner malt and also Weyermann's Premier Pilsner malt to choose from or I could go with Maris Otter.
I have a vial of White Labs WLP300 (my first liquid yeast!) on its way from the Malt Miller, it has an expiry date of 6/8/11 according to the website. I've read advice on here that stressing the yeast by pitching the vial rather than making a starter produces better flavours, any thoughts?
Lastly, what temperature is best for the ferment? I have an aquarium heater that I use in a water bath that I put my fermenter in, this is in my cellar so I can control temperatures down to about 14C with an accuracy of about +/- 1C. Am I best off fermenting at the recommended 20-22C or keeping it lower at 18C or so?
I do BIAB so there's no need to worry about stuck sparges and rice hulls

Cheers!