Rosat training would still happen since whilst Cell was a larger potential threat, #17 and #18 were still greater current threats. I assume he'd still go there, though without Cell interrupting, #17 likely wins the battle through his infinite stamina and would either KO or kill Piccolo. By the time this happened, however, Vegeta and Trunks would be closer to arriving and the latter would definitely destroy all three Artificial Humans. Vegeta would still likely go into the Rosat again after seeing how much Goku had surpassed him, Trunks returns to the future and Kuririn doesn't get his sexbot.
As for the Boo Arc, things progress in a similar manner until the fight with Dabura. Gohan likely wouldn't have weakened as much with Goku still around to train him every now and then, with him killing Dabura. Vegeta likely doesn't have the agitation to want to go Majin as the gap between he and Galu wouldn't be wide, so Babidi dies and Boo isn't revived. Super still remains not too different as Goku would still wish to find a way to fight Beerus and would ask Shenron, though #17 not being revived would mean the ToP at best ends in a draw if not a victory for Universe 11.