The first part of the third set also includes:
1. Bob couldn’t understand how the snake was able to sneak out of its cage.
3. Some Native Americans would call a(n) adobe their modest abode.
EDIT 1: And a stab in the dark (ignoring, for example, the sequences of letters derived from each set of clues):
Each part has an unknown clue. The third part's final clue could be (as a random example) Fir, Gang, Pip, and Ton -- which is then solved with ES giving the letter E. The ninth clue of the first set could use (PAIRS,PEARS), (PAIL,PALE), (PRINTS,PRINCE [a stretch]) etc as solutions, yielding the letter P. Then the second set's missing clue presumably solves to the letter S.
Whence we find the place where you are spending your vacation:
PSE -- or right here!
EDIT 2:
It seems we've found the answer but not the solution. Following mohirl's investigation into Right Words:
If we replace the first letter of each Right Word with the first consonant alphabetically to the 'right' of that letter we get:
EIGHT -> FIGHT
SANDY -> TANDY (?)
FLOAT -> GLOAT
GONE -> HONE
HELLO -> JELLO
RANKING -> ??
VOWEL -> ??
FORGE -> GORGE
NOTION -> POTION
which yields the letter sequence: F,T?,G,H,J,?,?,G,P,?
Or, alternatively unsatisfactory, we get a partial answer by noting:
One of the letters of the word RIGHT can be used to replace the first letter of each word to create a new word:
EIGHT -> RIGHT/TIGHT
SANDY -> HANDY/RANDY
FLOAT -> GLOAT
GONE -> GONE/HONE/TONE (allowing for self replacement)
HELLO -> HELLO (see above)
RANKING -> RANKING (...)
VOWEL -> TOWEL
FORGE -> GORGE
NOTION -> ??
This leads to the letter sequence only consisting of letters in the word RIGHT.
I have not got any traction on the letter sequences, although the third one is:
an anagram of 'AA MASSEUSE' -- presumably not as good as the AAA version.
EDIT 3:
The answer to the third pattern is
English (as in English Language Learners, the 10th most popular SE site) -- the top nine are Stack Overflow, Super User, Ask Ubuntu, English Language & Usage, Unix & Linux, Server Fault, Arqade, Ask Different, and Mathematics (SSAEUSAAM)
EDIT 4: A Right Word is a word that
forms another English word when you replace the first letter with the letter to the right of it on a standard QWERTY keyboard,
which have already been enumerated in Beastly Gerbil's answer.
