I just bought a new Rosary, and I haven't asked our priest in the locality to bless it.
Is there any danger when I pray the Rosary (or use of any "not-yet-blessed" sacramental for this matter) using this one?
Thanks for answering! =)
I think a priest would tell you that the danger is in not praying it, they're usually pragmatic like that.
Like some sacraments (Confession, Baptism) the intent is perhaps as important the action
Always remember that God exists outside of time and your prayers, in communion with the Saints are holy. Also, consider the fact that you could pray the Rosary nearly as easily without the aid of a rosary by counting your fingers and toes.
I don't know of any danger of a non-blessed rosary except for omission of prayer just because I don't have a blessed rosary. It's also completely OK to pray the prayer of rosary without a rosary as the item. The item is not really important, the prayer is important.
On the other hand, the intent of the blessing is to help my prayer, so it's not useless. You can translate the blessing as a prayer for the wielder of the rosary to pray well. This is not just the priest's personal prayer, it has the authority of the Church. The effect is similar to someone praying with you (probably not as important, but it stacks) - and every Christian know that it's completely OK to pray alone, but prayer of two or three is better.