DIY Lightning Experiment! Make a SHOCKING Capacitor

i have built it with my friends and i would very much appreciate if someone took their time and answer it :) (by the way big fan od the channel). i have only came to a small spark(0.5 cm-1cm) and that's The reason im asking.
1. is The magnet only gor aesthetics or does it actually have any effect on the size of the spark (because my physics teacher thinks it is probably not useful)
2. because i can't get a polycarbonate sheet i thought that a better dielectric material will produce a better spark (china,  or wet earth in a plastic beg which i used) 
3. does a steel and not iron cake pan have a big effect. 
4. and finally you have said in your video that you tried for Two  days before succeding. can you please tell me if its not inconvinient what were youre mistakes and how did you fix them. 
even if anybody doesnt answer thank you anyway and videos are great keep on the Good work :))))