Maybe - maybe not. The only TRUE way to tell 4 sure is TRY B4 you BUY. If you can't extensively test ride any bicycle before the purchase - don't buy it. It's as simple as that.
Frame sizing from one manufacturer to the next are NOT universal.
No. Not right. It all depends on how you are constructed yourself. That means how long your legs and arms are, the distribution of weight, etc.
First things first. Figure out what type of bike you need. I know you mentioned "road bike" but there are several different styles, models, makes, etc. so get it down to the closest choice before you do anything else.
THEN, go to a reputable shop, get measured, and get some idea of what size is appropriate for you. Ask their advice and select the right machine for you.