I find that it will generally auto-resize it for you. I think I tend to prefer PeakD since it shows how the post would look like but it doesn't help you make a good thumbnail though.
I tend to prefer a post with some pictures in-between because all text sometimes makes me lose focus and move on.
The error stated I was over the max size for a posting. Next time if I have issues with CTP frontend, I will try PeakD. Yesterday or the day before, I read a post on LeoFinance talking about posting tax. It showed that if you use a different frontend than LeoFinance for your posting your earnings are reduced by 20%. They showed screen shots to support their claim. Do you get less CTP earnings if you use PeakD or a different frontend?
CTPTalk frontend has mood swings sometimes lol so yeah PeakD is the best alternative.
There is no tax on CTP at the moment so you will get what you earned :)
According to what I know, I think there is no tax on CTP @jongolson or @elianaicgomes can clarify. There are front-ends with more steep taxes such as STEM which burns 50% but I think the rest tend to be fairly moderate with 10% or 20% of author rewards as the highest.