First Name field on ticket
 

I booked a Delta Vacation Package between JFK and ZRH for Jan. 2019. On www.delta.com when I retrieve my itn. my full first name + my middle initial (R) + my gender (male = MR) appears all in one: ABCDERMR in the First Name field, will this cause an issue when I c/I, boarding?

This is common (I've seen it on UA as well) and won't cause any problems.

This is DL's formatting. Last Name + Middle Initial + Title (gender does not appear on tickets).

This Mr. John Q. Smith will ticket as SmithQMr John.

For what it is worth, IATA standard only requires two fields. Thus, no need for either a title or a middle initial or name. Simply book as John Smith.