Keymapping

This should be saved to a default location under your main drive, which may be separate from the location of the rest of your Grim Dawn files.

For me it was under: C:/Users/[User]/My Documents/My Games/Grim Dawn/Settings

Opening the file you will see the following. The keybindings are set up in the following method.
{Button Action}: {Primary Button} {Secondary Button}

0: 0 0
1: 46 23
2: 31 0
3: 16 0
4: 50 0
5: 28 0
6: 25 0
7: 34 0
8: 35 0
9: 2 167
10: 3 168
11: 4 165
12: 5 166
13: 6 163
14: 7 164
15: 8 0
16: 9 0
17: 10 0
18: 11 0
19: 0 0
20: 0 0
21: 145 0
22: 146 0
23: 79 0
24: 81 0
25: 80 0
26: 147 0
27: 51 0
28: 52 0
29: 18 161
30: 19 162
31: 82 0
32: 32 0
33: 38 156
34: 17 155
35: 56 118
36: 45 0
37: 44 0
38: 29 107
39: 42 54
40: 57 0
41: 14 0
42: 43 0
43: 21 0
44: 60 0
45: 61 0
46: 62 0
47: 63 0
48: 64 0
49: 65 0
50: 33 0
51: 30 0
52: 36 0
53: 47 0
54: 22 154
55: 0 153
56: 0 0

The following are the actions that correspond to each number in the above list.

0: {Unknown / None}
1: {Character Window}
2: {Skills Window}
3: {Codex Window}
4: {Map Window}
5: {Chat Window}
6: {Group Window}
7: {Game Menu}
8: {Help Window}
9: {Quickbar Slot 01}
10: {Quickbar Slot 02}
11: {Quickbar Slot 03}
12: {Quickbar Slot 04}
13: {Quickbar Slot 05}
14: {Quickbar Slot 06}
15: {Quickbar Slot 07}
16: {Quickbar Slot 08}
17: {Quickbar Slot 09}
18: {Quickbar Slot10}
19: {Uknown / None}
20: {Uknown / None}
21: {Camera Zoom In}
22: {Camera Zoom Out}
23: {Camera Max Zoom In}
24: {Camera Max Zoom Out}
25: {Camera Default View}
26: {Camera Rotate}
27: {Camera Rotate Left}
28: {Camera Rotate Right}
29: {Drink Energy Potion}
30: {Drink Health Potion}
31: {Center Map (Map Window)}
32: {Drop Item}
33: {Personal Riftgate}
34: {Switch Weapons}
35: {Show Items (No Filter)}
36: {Show Item Tooltiops}
37: {Show Items (Filter Common)}
38: {Target Pet (Hold Key and Click)}
39: {Stationary Attack (Hold Key and Click)}
40: {Pause Game (single Player Only)}
41: {Toggle Pet Display}
42: {Toggle Party Display}
43: {Quickbar Switch}
44: {Select Pet 1}
45: {Select Pet 2}
46: {Select Pet 3}
47: {Select Pet 4}
48: {Select Pet 5}
49: {Select All Pets}
50: {Force Move}
51: {Move}
52: {Factions Window}
53: {Achievements Window}
54: {Interact}
55: {Pickup}
56: {Unknown / None}

I enclosed words and special characters with brackets. A pattern I noticed is that a particular line of the standard american keyboard tends to correlate to the number of the button. Likely a factor of the order in which each key is scanned.

0 - [Clear / No Keyboard]
1 - [`]
2 - 1
3 - 2
4 - 3
5 - 4
6 - 5
7 - 6
8 - 7
9 - 8
10 - 9
11 - 0
12 - [-]
13 -
14 - [Backspace]
15 - [Tab]
16 - Q
17 - W
18 - E
19 - R
20 - T
21 - Y
22 - U
23 - I
24 - O
25 - P
26 -
27 -
28 - [Enter]
29 - [Ctrl]
30 - A
31 - S
32 - D
33 - F
34 - G
35 - H
36 - J
37 - K
38 - L
39 - [;]
40 - [']
41 - [Enter]
42 - [Shift]
43 - [\]
44 - Z
45 - X
46 - C
47 - V
48 - B
49 - N
50 - M
51 - [,]
52 - [.]
53 - [/]
54 - [Right Shift]
55 - [Num *]
56 -
57 - [Space Bar]
58 -
59 - F1
60 - F2
61 - F3
62 - F4
63 - F5
64 - F6
65 - F7
66 - F8
67 - F9
68 - F10
69 - F11
70 - F12
71 -
72 -
73 -
74 - [Num -]
75 -
76 -
77 -
78 - [Num +]
79 - [Num 1]
80 - [Num 2]
81 - [Num 3]
82 - [Num 0]
83 -
84 -
85 -
86 -
87 -
88 -
89 -
90 -
91 -
92 -
93 -
94 -
95 -
96 -
97 -
98 -
99 -
100 -
101 -
102 -
103 -
104 -
105 -
106 - [Num Enter]
107 - [Right Ctrl]
108 -
109 -
110 -
111 -
112 -
113 -
114 -
115 -
116 - [Num /]
117 -
118 -
119 -
120 -
121 -
122 -
123 -
124 -
125 -
126 -
127 -
128 -
129 -
130 -
131 -
132 -
133 -
134 -
135 -
136 -
137 -
138 -
139 -
140 -
141 -
142 -
143 -
144 -
145 - [Weel Up]
146 - [Wheel Down]
147 - [Middle Mouse]
148 -
149 -
150 -
151 -
152 -
153 - [Gamepad Up]
154 - [Gamepad Down]
155 - [Gamepad Left]
156 - [Gamepad Right]
157 -
158 -
159 -
160 -
161 - [Gamepad LBumper]
162 - [Gamepad RBumper]
163 -
164 -
165 -
166 -
167 -
168 -

-Thanks to mikeydsc for helping me find the keybindings setting file.

- If you try to bind one key to multiple actions using this method, the action lowest on the list will have the key bound and previous actions with the same keybind will be cleared.

-If your keyboard has macro ability, you can set a macro to switch one and then the other. Set the delay between them to 100 (any faster and the game itself can't register what it was told to do) and then use that macro button to swap sets. (Thanks to Ojisan Kukkī)

-This guide was inspired by this discussion.