I have limited access to oils here in Mexico and have been using sesame oil I buy at store that sells oil to mix perfumes etc. I have yet to have any problem and have made more than a dozen batches and am on my 4th homebrew cycle. I think that the Whatman pretty much takes care of your sterilization.
As for the 2% BA, I use 3% in my tren brew....zero BB. It suspends fine, no problems. I recently brewed test p and had to use BB to hold it in suspension. I actually started with the standard 2% BA and I think 15 or 18 BB that is the default in the steroid powder calculator. I was getting sick everyday with flu like symptoms. I did some research and figured it was the solvent levels. I remixed at 3% and 3% and could hold the prop at 100mg/ml no problem.
Ive done a ton of reading and honestly the less solvent you can use the better. When I use a syringe to draw the alcohol up, if it touches the plastic where the numbers are written they will literally rub off. The BA is a must due as a bacteriostatic agent, but the BB in my opinion is optional.
Hope that helps.