Is it required that we complete this conversion? Can I just keep by NET tokens in my MEW account or is this activation required?
YES it is required. If you hold NET tokens you should proceed with Activations as soon as possible.
I bought my Nimiq on Liqui and don't want to do KYC. What are my options here? Am I pretty much going to be forced to sell now?
You can wait for NET and NIM to be listed simultaneously and trade NET-BTC BTC-NIM or something like that.