should be absolutely safe to fire; if anything it is safer now. I had a T-54 that I removed the remnants of the safety from, to improve functionality.
The safety is cheap and poorly made; it would bounce to and from safe to fire easily. One of the screws holding it in place eventually crumbled, causing tiny bits of metal 'sand' to jam up the slide. Removing it and a good cleaning restored complete functionality.
If you're hesitant about the appearance, then check into aftermarket grips that cover the safety holes. Grips4U sells them, I think others do too.
Half-cock is okay, or carry condition 3 (empty chamber). As you would have to thumb the hammer back anyway, racking the slide isn't that much slower, and a lot surer of a safety.
I had (and still have one) the T-54, which has the wider magazine. What I understand about the 213 is that there is a spacer in the magwell, that if knocked out, will allow for regular Tokarev mags to be used. My T-54 was in 9mm and all I ever used was standard (7.62) mags, never an issue feeding, cheaper and easier to find the mags too.