So I may want to join JLTP on this year on july and December as a way to see my ability in Japanese and maybe it is a good addition to my CV. So having a very horrible writing in writing kanji may make me fail it.

What are your experiences for those who has taken them?
Also can I take like level 3 in july then in december level2 on the same year?

Thx

No need to write any kanji, the JLPT is multiple-choice. Yes, you can take any level at any time.