There is SO MUCH we need to see before the show ends. I know some of this will be answered and some arent that important,but there are some others that are big and i dont think you can put all this into 10 episodes that will mostly consist on the Stan twins and Bill Cipher.
1) How did the time baby escape?
2) How is life in the future?
3) Who was Mcgucket´s ex wife?
4) How did they construct the portal?
5) What´s on the other side of the portal?
6) Bill Cipher´s past.
7) Why are there so many monsters on Gravity Falls?
8) Are there other gods?
9) Robbie´s past
10) What´s up with Gideon´s mom?
11) What happened with Carla?
12) Dipper and Mabel´s parents
13) Why do the northwest have tapestry with bill cipher on it?
14) What´s buried under gravity falls?
15) What happened with clone #3 and #4?
16) Who or what is gompers really?
17) Is Blind Ivan a Northwest?
18) Who was the third member on the mystery trio?
19) Does Stan know who bill cipher is?
20) From who was the author hiding the journals?
21) What is Bill Cipher´s big plan?
22) Who is the “true villain” of gravity falls?
23) Does Dipper´s birthmark have any meaning?
24) “The Handyman Knows More Than What You Think”
25) How was Dipper and Mabel´s life before gravity falls?
26) “Stan Pines Dead”
27) What does the cipher wheel mean?
28) Who is Dipper and Mabel´s grandmother?
29) Why wasn´t Gideon´s dad affected when gravity fell?
30) What have the agents seen?
31) How long has time passed for the author?
32) Why are there so many people with one eye on the future?
33) Wendy´s mom
34) Why does robbie have no reflection on mirrors?
35) How did the author get the sixth finger?
36) Stan´s tatoo
37) Are the dinosaurs going to escape?
38) The Royal Order of the Holy Mackerel
38) Why are there so many triangles in the mystery shack?
39) Who or what drove the author to write in invisible ink?
40) How did they fund the portal?
41) Dipper´s Real Name