Hi, 

Have you tried business rules for forms? 
You will have several of them. 

can you elaborate? Business rules as I understand them are meant to hide or mandate options. But I want to have the guests first and last name fields dynamically added so the requester can use the same form for any random number of guests instead of creating the same request over and over again,

Don’t think there are dynamic way to do it. You need to add all fields and maybe have a dropdown that say 1 - 20 then you show the number of fields using rules. 

I do this exactly this way. 
dropdown box asking how many...
then using business rules, this shows/hides the relevant boxes for each. 
 

All done via business rules

If you are collecting the same information for each guest, why would you not just have the person entering the information one guest at a time?

Looping through unlimited replication of fields, I see many things could go wrong in that scenario especially with required fields.  Guest 2 has a typo or invalid data you would be scrolling back and forth to fix those.

Could you just allow them to attach a spreadsheet or use some outside solution to to dynamically generate individual SRs based on things in the spreadsheet. 

I realize though it also depends on what you are doing with that workflow after the SR is submitted.  Just seems over complicated workflow to continue to loop through the fields to then process them as well.

I just googled how the competition is dealing with this.

What they do is pretty clever: They have just one line with the fields I wrote like “Guest Name, First Name, Mail” then there is a little “plus” sign in the end of this line.

Each click on the “plus” sign will add another row with the exact same fields which can be filled in.

In the result this will create a table with the required fields as a list.

This solution looks promising. I would love to see such a thing in FreshService