Yes (or at least, not an emphatic No) to the Constitution, Maybe / Don't Know to Euro.

[Looking at the answers above, I may have just got myself banned sine die from a number of Sessions I have yet to attend, but let's go down fighting.]

I see little instrinsically wrong in the Constitution.

The Euro could do with a few more (enforceable) guarantees regarding interest rates and debt management, but it doesn't seem to have reduced the Irish Republic to a dependent banana state.