All answers are in the disassembly!http://www.romhacking.net/documents/401/
The routine which draws the title screen is "EnterTitleScreen" in bank_0E.asm, line 3487.
If you make the text longer, you will have to change the box size/position:
0x3A170 = X position of both "new game" and "continue" boxes
0x3A174 = Y position of "continue" box
0x3A178 = height of both "new game" and "continue" boxes
0x3A17C = width of both "new game" and "continue" boxes
0x3A192 = Y position of "new game" box
0x3A1CB = X position (in pixels) to place cursor for both boxes
0x3A282 = Y position (in pixels) to place cursor for "Continue" box
0x3A283 = Y position (in pixels) for cursor for "New Game" box
There isn't a pointer table for the text -- and instead the pointers are hard coded in the drawing routine, much like how the box sizes are.
As for how to solve your text problem.... the game actually does support DTE here. So if you take advantage of DTE pairs you might be able to fit more text into a smaller space.
Also, the same space is shared for "Continue" / "New Game" / "Respond Rate" text -- so if you use less space for one of those strings, you free up space for another one.
Of course, doing that means you'll have to adjust pointers.
The problem is there is no pointer table for these strings -- and instead the pointers are hardcoded in the drawing routine:
0x3A183 = low byte of pointer to "Continue" text
0x3A187 = high byte of "Continue" ptr
0x3A199 = low byte of "New Game" ptr
0x3A19D = high byte of "New Game" ptr
0x3A1B3 = low byte of "Respond Rate" ptr
0x3A1B7 = high byte of "Respond Rate" ptr