We had two young toms (neutered) in a row. Both got hit by cars.
When Rufus died, I was totally upset. The experienced Vet said males do this, dumb things even if neutered.

Females on the other hand, are smarter, stay closer to home, and behave. They seem to understand danger better because they are programed to take care of kittens.

Eventually, we got a new kitten, our black and white. I didn't let her out until she was 6mos old. At first we went out with her every time. But she is reckless to some extent too. Up North she tended to run off and get lost. Prompting search parties on the island. She is now 6 yrs old and a bit more sedate.

I think alot depends on the cat. Females tend to be more sensible...so the Spice Girls may stay close.

I would not let Shadow out alone...maybe he will grow more sedate later, but with his neuro deficits he shouldn't be out when you are not out. I'd have to see Shadow in action, to give a more accurate suggestion.

We trained each cat to come when called. That helps ME be less anxious.
I have a funny noise I make and they learned that food treat follows, so they are now pretty good at it. I am more or less decided on a small dog when Sheba passes, however. I don't think I'll have 3 cats anymore.

The "fear factor" is hard to deal with... so alot depends on the maturity of the cat. If the cat has dopey qualities (like Rufus had)...well, those are the ones you worry about. If you have a cat door, this is also helpful. We have 2 cat doors, one leading to a screened porch and one to the upstairs bedroom. For 3/4 of the year I have that window open, and Tippy and Oreo can come and go (Sheba can no longer jump up to use it). I have found that with a cat door they tend to stay in more...strange as that seems. Cats HATE closed doors, so if there is access all the time, they tend to come home and stay here more.

Smart sensitive people tend to react to loss severely...I don't know how to tell you to moderate that. It is really hard to deal with.