Glad that I could help :")
You can watch the showcase video tutorial for WP Pipes in here to get a clearer image of how to make Pipes work for your benefit.
About your specific problem, I nominate the Cut Introtex Processor as a solution. Please click on the link below to view the field mapping:
Fields mapping for introtext with custom length.
The Words option for Cut introtext processor would decide the minimum number of words to be cut from po[2]html, the returned HTML string will be stored in po[3] introtext. You can use it for [di] content to post with a shorter content. Remember to set the value as YES for the Finish Sentence option. You should also check if the Remove option in Get Images processor is set to Yes, to ensure that there would be no duplicated images in your auto posting.
The "link to original source" question has been answered in this thread: Giving credit to source?. Please go there and read. If you still have question, please don't hesitate to ask here again.
Best regards.
