Q1: Short term losses are used first. You can't choose.
Q2: Yes and there is no limit to how much can be used against realized capital gains.
Q3: Yes
Q4: Yes
Q5: Not sure what you're asking, exactly. Carried forward capital losses are first applied to net capital gains. If there's loss left over after that netting amount then $3,000 of the remaining capital loss is allowed to be used to offset "ordinary" income.
Q2 addendum: You're preparing a tax year 2019 income tax return in 2020 so apparently your "2019" numbers are referring to the 2018 tax year, and your "2020" numbers are referring to the 2019 tax year. So what you're seeing is the "netting" process.
