Keren,

Given the situation I would not pinch them at all unless they produce too many flowers as that would just hurt the quality of the fruit you get. Figure on good stems 6 fruit buds.

There is nothing wrong with planting older bushes. A few years ago I picked up some 7 year old blueberry bushes from a commercial grower who was switching to earlier ripening varieties. The plants were growing in 30 gallon pots and were only $10 each, he had 1000's to sell......how could I say no? They were so big I used my tractor bucket to lift them and remove the pots then in the ground they went. I still have them and they are still producing beautifully.