I didn't want to add Census sources for each individual location either. I used the for example source template Census,US 1850-1870 filmed and created a source template for each state that I research. This does allow the population schedule reference to be included in the citation. So I have a template for each state, Tennesse, Alabama, Florida, etc. with the census year. Then when I find a census document for an ancestor, I use the copy source function to copy the state template and edit the copy to show the county. US Census 1850. Florida, Duval. I use the information provided by Family Search, Ancestry or another provider to record the data, Film number, roll number, household id, page, head of household name, etc. I also use the detail notes to record if the name that was shown in the index was recorded incorrectly for some reason. This way anyone looking at my sources can go to any posting of census images and find the same image.
The NARA identifying information will not change whether you are looking on line at different websites or on microfilmed data.
This way I can also sort and find all the families in a particular county for a particular year.
I don't include the date I viewed it for census documents. I may look at an individual document several times to verify household membership, neighbors, etc.
Once the microfilm data has been entered for a county, it pulls forward the next time I access it and I only have to add the enumeration district, household id number. etc. This helps because if more than one family is in the county at the same time there is less information to be entered.
Hope this idea helps