Malevolent Whispers - attacking and effects?

I’ve tried to use this card several times, but I’ve never been able to attack using the creature I control.

If the creature is summoned, and I immediately take it while it’s still disabled, then I assume I can’t use it because it’s disabled.

But if I take it on the next turn, after it’s gotten the chance to attack one time, I should be able to attack with it, right?

Also, I took control of a creature that gives life when it enters the battlefield. I don’t remember which one, sadly. When I obtained it, I got no life, but when my opponent got it BACK from me, my opponent got life a SECOND time - is that working as it should??

I confirmed that obtaining a creature when it’s not disabled will allow it to attack.

Still not sure why my opponent got life when he got the creature back frim me.

Confirmed problem with enter the battlefieldeffect - I just used malevolent whispers to take control of “ghirapool gearcrafters” (spelling is likely wrong).

The gearcrafters bring a thopter into play when they’re cast. When I take control of them, I do NOT get a thopter. When my opponent gets the gearcraftwrs back, they get another thopter.

I took control of the gearcrafters with whispers 2 times in that game, and the issue happened both times.