2 BP is enough?

Yes it can clear the shop with 2 BP. Farming gourds in 2 BP is more efficient than 3 BP for you are likely to put drop CE rather than damage CE.

2 BP is enough if you can do it 300 times in 2 weeks... That is 600 BP and in 2 weeks, you have 336 without Rice Ball recharge.

2BP is enough to clear the shop, provided you have a gourd drop boosting CE in your backline somewhere.

However, it is NOT enough to get all the DP rewards, using all your Onigiris will get you to around 150,000 on the DP ladder, which I would say is pretty good, as it as all the apples, tickets and common/silver ascension mats. You only miss out on some scales, talons and greases