I import symbols (pdf) from LaTeXiT to Illustrator. When I keep them in Illustrator, I feel the symbols are of different font sizes. For instance, if I bring a and l to Illustrator, their font sizes look pretty different. How do we ensure that symbols are of the same font size?

I try to generate a pdf file using a code that have been working for more than 2 year. Now I get following error message:
! LaTeX Error: File `tabu.sty’ not found.

i want to small the font in itemize so i try to new a newenvironment to do this.the code i write in .cls is like this.

Could someone please help making the posted complex table in latex.