Hi,
as you saw, it is not (not yet?) possible in the *.txt file to switch to bootstrap buttons.
A chance may be to investigate the lss file.
Just create a small survey with two questions, one as bootstrap buttons, one as list(radio), export and compare.
Mabe you can do a simple "search and replace".
lss ist a simple text file. You can open in any editor (notepad++, o.ä.)
1300 questions seem to be a lot.
I am rather sure that the LimeSurvey hosted installation uses the InnoDB engine of MySQL.
But this only allows 1000 columns.
See the manual.
[url]
www.limesurvey.org/manual/General_FAQ/en...egarding_survey_size
[/url]
To be sure, try to activate your survey.
Joffm