Do you need to be a werewolf to complete the Companions quests?

I got the quest to meet under the Skyforge to become a Werewolf and I don't want to finish this. However I'm not seeing any other quests from the companions.

Do I need to become a Werewolf for more quests?

Yes. In order to finish the Companion questline, you must become a werewolf. It's pretty crucial to their plot.

Yes, and it's crucial that you keep the ability until you are done with all the quests. The reason is that some quests will require the ability to be present (tho not active) in order to complete OR interact with them properly. A good example I struggled with myself was "Totems of Hiricine".

You are able to remove your werewolf ability trough a quest, however, doing so will render you unable to complete what requires the ability. "Totems of Hiricine" is a quest that leads you into an area only werewolves (need confirmation) can enter. It seems a later patch added the ability to regain your werewolf ability, but I've yet to confirm that resets that specific quest line completely, or it just bugged out for me in another way. Point is, keep it, as you can control it as just another ability at your leisure.