I did not understood merit fulfill yet. I was reading past few comments in this thread, but didn't find any concrete information. So, by your words if you do not give or get Merit your rank's raise is kinda going to be frozen, is it really so? Prove or unprove this to me somebody, please 
If you continue with this attitude you will be a live proof with frozen rank yourself. Regarding your question, you need to get merits to rank up. Giving merits has nothing to do with ranks.
It is up to you.
You can use your account to merely read posts. You do not have to post in order to continue with your privilege to read threads.
Also, you do not get merits by sending personal messages. I have been a member of this forum for nearly 4 years, and I have averaged the sending of less than 10 personal messages per month.