Yes you can mix different brands but I recommend you do not mix different weights. You can even mix synthetic oil with conventional oil. But as the weight of the oil is critical, do not ever mix one weight of oil with another, no matter if it is synthetic or conventional oil.
why would you want to? Yes you could, the viscosity will average out .
Who told you it is not recommended? You can mix synthetics as long as they are of the same weight. You can even mix synthetic with conventional oil.
No, and do not mix. They are different viscosity and different type oils
Sure, why not? I mean, there's nothing bad about it.
Manufacturers mix various oils to make an 'SAE 40' oil product. Such a mixture will not have a molecular weight.
Even if you can it's not a good idea. These oils have different viscosity and might have different chemical content. When you mix the oils it can change their mechanical properties and the oil will not be as good as when they are separate. You can get special additives to tune 5w20 in something in between 5w20 and 5w30.
No they are to very different oils same purpose different applications.
Yes, you can mix them.
Nothing if they were approved oils. You can mix 10w30 with 5w20 etc. Not a good idea but you can do it. You can mix brands with no problem.
Two different oils. Cannot be recycled or reclaimed.
no it is not ok because they are two different oils and it can mess up your engines