Hey thanks for a comment on a fairly new forum. I'm going to start sending people here because the email inbox is getting busy and I'm repeating myself daily sometimes hourly

In short the answer is yes the plugin will setup your custom fields for you in every post.
CSV 2 POST Free Edition allows it but is slightly restricted. It is however worth trying out to see the interface and get a preview. I've not found a plugin like it yet that avoids you having to mess about too much with your csv file. I just released version 2.0 minutes ago for the free version and 0.5 for paid version which I believe is better than one I found for $100 so any feedback if you buy this is appreciated.
Fingers crossed there is no bugs I've missed during testing.
The thing about the free version is that it is all manual.
CSV 2 POST Plus the paid edition has "Automated" settings which allow you to both automatically create categories based on a selected column of data AND you can select an automated setting so that it will automatically create custom fields. If you go automatic then every column of data is used in custom fields. The identifier or key is the name of that column so think ahead!
In most cases you will name a column of data by what the data is and your custom fields are the same however custom fields might require something very unique with underlines or whatever. If your data is still to be exported then try to name the columns to match the existing custom field identifiers used by your theme.
Or if you have the choice of setting up custom fields manually and you write in your existing identifiers then assign a column to them. This may suit you if your theme is very complex in using them.
It's possible to go auto and code the theme to look out for two different identifiers for each piece of data but thats really pushing it I think. I'm sure another the other approaches will be more suitable. One issue right now is the custom fields page has only 4 you can setup for unique values per post. If you felt you would like to do it manually but need fields then I'll code more in for you.
All that I just wrote covers Stage 4 of the new campaign process. You mentioned "Post Content Layout" which is totally different area of the plugin and is the file that styles your posts as in the information visitors see rather than the hidden data. I create these on request for free.
More InformationOther info I should put in is that the plugin is more suited to none shared servers with less restrictions e.g. free hosting or reseller hosting. Full processing (the entire csv file) is not allowed on low cost hosting because it is too powerful. Even staggered with the paid version, depending on your settings, can upset low cost hosting. Alternative can be to use it localhost with a local blog and develope there before moving online.
Won't go on about that stuff as you may know already.
Let me know if you have any more questions.
Ryan