How is this compared to the Theives brand?

Thieves smells nice, but it is sold under a multi level marketing scheme. If the products are so good, why can’t you buy them like any other product? You can find some on amazon, but it is all sold by people desperate to get rid of product they bought from the company and are desperate to sell.

Will the multi-surface cleaner kill bacteria - such as cleaning up meat, pork or chicken juices when doing prep for cooking??

According to the Mrs. Meyer's website: "No. Our Multi-Surface Everyday Cleaner will not disinfect. The Multi-Surface Everyday Cleaner is a very effective cleaner and offers excellent soil and dirt removal, but it does not offer the anti-bacterial benefits of products containing chlorine bleach. When disposed, products containing chlorine bleach are harder on the environment and their fumes also pose a potential health risk to consumers. There also is a growing body of evidence that points to the formation of resistant ?super organisms? due to overuse of anti-bacterial products."

I recently purchased the bornku brand multipurpose scrubber. would this spray be suitable for cleaning both the kitchen and bathroom?

I don't know what bornku scrubber is, but the cleaner is good for kitchen and bathroom.

will this clean the grime/grease from kitchen cabinets and how much to dilute it for that purpose?

This is a concentrated formula, I use the directions for dilution, it lasts a long time...I use this for EVERYTHING...floors, counters, chrome, and even oak cabinets...I also use it in my shower...for my chrome fixtures, I spray and leave for about 10 minutes, come back and rinse and dry...they come out sparkling clean...streak free...for my showers I spray heavily around the top of the shower (let it run down the showerwalls) and very dirty spots, let sit, and come back in about 10 minutes, wipe out and rinse...no scrubbing. This is the best all purpose cleaner, no toxic, and doesnt burn out my lungs. Cleaning your Cabinets, use regular dilution, I would spray lightly, let the spray work its way down the cabinets...then walk away for about 5 minutes...wipe down the cabinets and counters under them after the dripping...Kitchen grease can get sticky...and you may have to do it again, depending on how bad the grime is.