Sandboxie Support

I found that I'm unable to set default web browser just for the sandbox, would be nice to do so and let it stay so even after clearing contents of the sandbox.

1. I have Chrome as default web browser and FireFox installed, I use them both outside the sandbox.
2. I want FireFox to be my default web browser inside the sandbox
3. I want FireFox to open internet links from opened from inside other sandboxed applications

Can't do that now despite the task seems pretty easy and essential.

There is no such setting. If you have Chrome as your default browser, the links you open with other software sandboxed will open with Chrome browsing.
There is no bad in that, Chrome should be just fine sandboxed. Better than having it unsandboxed despite that theoretical thread in wilders forum.

My default browser is Firefox. It is configured so tightly with NoScript that sometimes it is a bother to have it opened instead of Chrome, just saying