If I keep my data on OneDrive do I need to worry about ransomeware?

Yes. The files are still on your computer and synced to the cloud. HOWEVER; if you uninstall the software from your computer and only go though the website, then yes you will be safe (assuming they don't get access to your onedrive account).

Nothing you can do about ransom-ware other then preventative measures. Use google chrome with uBlock extension and you will be pretty safe. Get some antivirus as well.

Yes. The common way ransomware can damage backups is not the ransomware itself, but the bad practice of using overwrite backups. If you have only one backup that is refreshed/overwritten each day in the Cloud, the damaged files will overwrite good ones. Make sure you have a fresh backup area for each backup to avoid this.

Yes. Because OneDrive synchronises its information to your local device, then it is susceptible to ransomware. So you should also keep a backup copy on an external disk that is only connected to save info about once a week.

Yes. ANY file your computer can see can be infected by any malware.

no one drive is pretty safe, unless they get hacked