As a rule of thumb pinstripe should only be worn as a suit. However given the many associations people make with the pattern I would avoid it altogether. Try FlyingMonkey's advice, he knows what he's talking about.
Forgive me if this has been commented on recently and I missed it, but what are the general opinions concerning Meermin's quality in relation to other familiar brands such as Alden, Carmina, and Allen Edmonds?
Concerning the henleys:
1) When are they expected?
2) What colors? (Fingers crossed for wheat and heathered grey)
3) How deep is the placket? (I've not been a fan of henleys that have a shallow placket.)