Roy Tang

Do I send myself back and take the place of my younger self or just appear in the past as a chrono-intruder ? If it's choice A, sure! I'd take a redo and see what happens. If it's B, enh, that's a bit pointless. I'd have to stay in the past to make use of my future knowledge; if I return to the future, either I annihilate myself because I would have ended up a different person, or it's an alternate universe anyway, in which case I only changed some other universe that might have been different even without my time travel.

You send yourself back and take the place of a random member of New Kids on the Block

If I have a time machine, can I also have a machine that allows me to jump from one reality to another parallel/ alternate universe?

Sure! Then I could 'write' boy band songs that haven't been written yet by the Backstreet Boys, Take That and N'Sync, becoming the ultimate producer of boy band music! Though it would be cooler to go back to the 70s and meet David Bowie at a party, like in the Flight of the Conchords song.

After the 10th episode, I think a real Quantum Leap guy would get tired of trying to 'fix' history, and just start messing around for fun.

Quantum Leap guy wasnt trying to fix history, he was trying to get back "home". Anyway seriously, it's B to your first question.

James that didn't end well for the Sliders

Well, he was trying to fix the history he'd mess up by jumping into whoever, so that he didn't change it. I would've given up on trying to get back home after taking the place of a person with a decent enough life. If B, yeah, totally not worth it. I'd only do it if I was trying to prevent or solve some apocalyptic problem of our time, like in 12 Monkeys. If it's incidental, what for? It might be fun and historically valuable to watch the past through a tachyon viewer, but going back in the B situation is all risk with little chance of reward.

Ah, wait. Maybe if I could go back, say ten years, open an online trading account I did not know about, invest wisely with hindsight, then go back to my present self suddenly 'discovering' the account in my name that has accrued huge value… That wouldn't risk much, and I would gain in 'the present.'

Go back to 1960s and invest in a dollar account. By today, we can be Corona-rich.

James Canaveral but don't forget to pay your income tax

ako kahit 30mins to the future lang.830pm ang huling taya sa lotto, 9pm yung result.

pag may binago ka kaya sa future, may masisira kaya sa present?

may mababago pero ibang timeline na. hindi na sa timeline na nais mo ifix.