Yes, what I mean is that it could be something smaller. I am not a transmission tech, but bits and pieces of the story suggest this might not be a total transmission teardown issue.
Think of it this way: an auto transmission works by having fluid pressure applied to clutches. Think of a clutch as two disks that have to get mushed together really hard so that one disk spins the other one. That's basically what is going on in there.
So, going by the P0730 (though there could be more problems!), you have some slipping going on. That can happen because the clutches are just worn out and can't grip each other anymore. But, if that was true then a) a trans tech should have found an amount of "clutch mud" in the pan that pointed to an issue; b) it wouldn't only be an occasional thing.
That leads to wondering about having enough fluid pressure top apply the clutches. Improper pressure can come from bad internal seals - the fluid basically gets shot down a passage, but it leaks so the pressure can't be kept up. This would mean a teardown. But, it can also come from - yes - "electrical" issues. That could be power problems to supply the solenoids that control shifts and provide fluid pressure. Or it can involve a problem with solenoids themselves.
On another note entirely, while the P0730 codes certainly points at the transmission, there are plenty of quirky engine issues that can mess with the transmission. E.g. MAF & TPS sensors are two important things, and quirky behavior on their part can result in the computer doing all sorts of wrong things with transmission controls - including not providing appropriate line pressures.
Of course, I'm just blathering vaguely based on very little info. The bottom line is that someone who knows something and can inspect the thing and put it on a scanner has to do that. The right scanner will tell a tech what the solenoids are doing when. The fluid pressures in the transmission can also be measured and evaluated. You still need a diagnosis.
If you're lucky our resident transmission expert will stop by and you can hear from an actual tech.