ex dividend question

Advice please:

I'm new to this game

I'm considering a strategy of trading blue chip companies for mid term profit

1. Buy a blue chipper -high yield- about 1-2 months before ex dividend
2. Receive dividend plus gain any possible capital gain due to share price increasing in anticipation of the dividend.

I have a few questions:

To get the franking credit do you have to hold it for 45 days? - and is it true that if you gain less than $5000 in franking credits per year this doesn't apply.

Can you buy 1-2 months before ex dividend and sell a day before ex dividend and still receive the dividend? - this could be a stupid question - as it would seem that selling after ex dividend would mean some capital loss due to price dropping after this date

what is the minimum time you can hold a stock to get the dividend?

Any general tips would be appreciated as I'm not sure if this strategy will work

Cheers