Substitute vegetable oil for olive oil

It's certainly safe. Butter, Oil, whatever, it's more about taste than anything else. Some people even push lard and butter as the "safe" options, because they require less processing than oil, and much less than margarine.

One thing which you should be aware of in regards to butter vs oil: butter has a significant amount of water in it, so you shouldn't substitute 1-to-1, or you will have a stronger flavour (and more fat) than perhaps you want.

If you're accustomed to salted butter, adding some salt will help ease the transition. If the flavour of olive oil is off-putting, there are plenty of more neutral flavoured oils that have a similar fat composition, or you can simply avoid extra virgin olive oil*.

*extra virgin olive oil in the U.S is largely a scam. In most of the world (countries that adhere to the IOC standard) this signifies "First Cold Press" olive oil. In the US it signifies "lamp grade olive oil with green food coloring". There are no restrictions on the use of terms like "extra virgin" in the US, so you can't guarantee that's what you're really getting just because it's on the label.

If you're trying to avoid char, then switching to honey or any sugar is probably in the wrong direction. Sugar burns...quick.

I'd recommend three things overall specific to this crust:

1. Use less oil. If your oil is dripping off in buckets and causing significant fires - you've got too much. Just try a light brushing on the meat.

2. Use a different oil. EVOO isn't recommended for grilling mostly because of it burning at lower temps. It turns black, kinda nasty, and loses all its good flavor if it goes too long, too high. You can try extra light olive oil or really just a more standard canola or peanut oil.

3. Use the lid on your grill. A real fire in your grill consumes oxygen fast. If you leave the lid off, it can burn for much longer. With the lid on, fires are much much shorter. I'm an avid fan of grilling with the lid on and I never knew why people complained of flair ups till I did something with the lid off, its a lot worse for flair ups.

A general steak tip, especially for something like this with a crust - make sure your steaks are at room temperature before they go on the grill. If you're starting with a cold steak, you're going to have to grill it longer and there's a much greater risk to burn the crust.

Also, consider a quick sear on each side over direct heat till your crust gets the color you want, and then move it off to indirect heat to finish.