Hi TS,
I like all the horses that you mention. I can't even pick 5 horses for my Trifecta. Those I like in your list are Doubting, Serenade Rose, Cayambe, Beauty Watch, Empress Lily, Assertive Guest and Mary Marvel.

The disadvantage that I see in them are :
Doubting - Not an impressive win on his last run.
Serenade Rose - Don't know why the odds are at double digit.
Cayambe - Last 50m wasn't that impressive on last run
Beauty Watch - Might get too back in the race.
Empress Lily - Barrier 18.
Assertive Guest - NOt a regular jockey (M. Zahra)
Mary Marvel - NOt a good strike rate although making a lot of ground in her last run (3rd).

Do comment.