1 I am a full time employee in ON. Should I register to corp my rental business in Sk? 2. Bought appliances in ON but will bring to SK. How will we prove it for filing?

Hi @elac981549 

As we do not have access to your full financial situation , we recommend to  consult with a Turbo tax expert  who is familiar with the tax laws in both Ontario and Saskatchewan to determine what's best for you . Use the article here for help 
https://turbotax.community.intuit.ca/turbotax-support/en-ca/help-article/tax-return/contact-us/L1h8P3E0x_CA_en_CA?uid=lvmq7fdk