Agree, stick to 7sage, LG part is so far the best. If you need some supplemental materials for LR and RC, I would recommend Manhattan for LR cuz it has great fundamental explanations for Assumption family questions, and Trainer for RC for the same reason as zwoerner just said.

Yeah, I think you are right. This "and" can translate to "some", which depends on your needs.

check these two lessons "Advanced: Negate All Statements" and "Deny the Relationship" under Some and Most relationships section.