You'll do fine, lookin forward to some pics when you are done.
I think I've only "planted" Java Fern once... and frankly that was the one that has grown the least of all the ferns I have had. I wouldn't
Now that I have retired from biology teaching after 35 years, I am ready to get back into aquariums on the home front. At school, i had several tanks,
You don't have to but they would be happier and you'll likely see them out and about more often. I wouldn't worry about overcrowding. They're only 2"
Personally I'd use 3/8 but you should be ok with 1/4 so long as you don't bump it real hard. Also I'd suggest using weld-on 40, tilt and pour method