The answer is NO!!!! and YES!!!!
No one can know the future except for G-d ! We do not predict the future, תמים תהיה עם ה’ אלוקיך.
The way to predict someone’s future through handwriting is just to be able to see that person’s personalities. If you know someone’s personality, you have with what to try to predict what the person will do in future situations. Of course, he is able to change as well, and when the person changes so will the handwriting.
The usage I have most out of handwriting analysis is that I use it to guide me what questions to ask. Where to search for some underlying issue. It shows me what is hot and what is cold. I can go straight to the underlying issue using this tool.
Another point to take into consideration about handwriting analysis. G-d does not create any bad middah, any bad characteristic. Every characteristic has a time and place. This means that signs of handwriting analysis can be always taken two ways, positive and negative. For example.
Small letters mean that the person is low self esteem. The good interpenetration of this might mean Humble. Doesn’t make much noise as is focused.
The negative interpretation might mean: shy, reserved; low self confidence.
Sometimes they are both true. Sometimes the graphologist needs to decide how small is considered normal. Anything less than normal can show some extremity which is never a good thing. We always strive for balance.
So regarding telling future through handwriting. I do not recommend it. There are too many possibilities for interpretation. People change. And the future has so many factors that it is dependent on.