Will my 1.5yr gap in the undergrad affect my gradschool/summer app UK?

Hello WSO community,

BG: After I finished my second year ug in London, I took a placement year working. 7 months into my placement, I went back to my home country due to an unfortunate situation with my family and took a gap year. (that would be 1.5 year gapped after the 0.5 year from my placement)

1. Now I'm preparing for grad school/summer for this cycle. Should put a line or two on my CV to explain what happened or simply let it left blank? It was quite of a sudden and emergent situation so I wouldn't say I left my placement on good terms. Will this come up as a problem, say bg checks etc.?
2. In addition I have some problems abt the programs. Do programs matter if the school is a target? (I'll recruit for S&T) I'll do Oxbridge, LBS MFA, IC MiF for sure, but for LSE, the MiF acceptance rate is 1 in 20. Should I instead do MFE(which is 1 in 19) and a program thats easier to get in like Finance and Risks (1 in 12)? Also for UCL what programs are recommended? And if there are other UK schools I should look at. 

3. I have a borderline distinction in Finance at a semitarget undergrad in London with one non-bb springweek and 6 months of placement experience at an allocator/AMish shop. My Gmat FE is 705 (gonna take it again for a better mark). Do I have a shot for Oxbridge, LBS and LSE MiF?

   I know thats a lot of questions. Any Insight you can share would be appreciated.