time dilation vs aging

i'd like to start a conversation about time traveling and how it affects aging if anyone of you are up to it.

time dilation works like this...

a train that is going down the tracks has a rider who is bouncing the ball off the floor. I I I I The speed of the train isn't relevant yet

an observer not on the train sees the ball bouncing but although the distance between the ball and the floor stays the same ( I ) the ball travels a further distance ( V )

this is the definition of time dilation

now according to Einsteins special relativity as the train approaches the speed of light supposedly time slows down and aging is slower. To me this is not the case since that distance of the ball to the floor would remain the same. The balls mass would increase due to speed and to the outside observer that ball would be travelling in a straight line
( ----- )

the elapsed time of the ball hitting the floor would be non-existent to the outside observer and yet the ball will still hit the floor at the same intervals since that mass increase is only relevant to the train and not its passengers who are along for the ride even though they are traveling just as fast otherwise the ball wouldn't be hitting the floor at all either at some point

Now quantum mechanics says the change will affect the rider and ball yet I have my doubts and let me explain it this way

if you are in a car traveling at 10 mph and threw a ball forward at 20 mph the ball would be going at 10 + 20 = 30 mph yet science is telling us that nothing can travel faster than light so if you were doing light speed and threw that ball forward at 20 mph the speed of the ball is only light speed.

I have always had an issue with science teaching this since light speed + 20 mp = lightspeed + 20 mph not lightspeed alone.

you can't add something to something and not have it show up in the end result and thats basic physics, for every action there is an "equal" and opposite reaction otherwise it isn't a valid equation.

so according to the time dilation experienced the observer would age faster than the rider and again, to me the elapsed time remains the same regardless of how fast you are going because the train might break that barrier but the rider is still a rider and I am doubtful that even the train will age slower.

The reason they come up with this theory is to explain what happens if you follow a stars light back to its source and as you get to its source it hadn't reached earth yet but again it is the elapsed time that is the issue not the age of the light regardless of viewpoint.

the formula is speed = distance / time
therefore time = speed(distance)
and distance = speed(time)

now the variable science gives us for breaking lightspeed is increasing mass but for one thing this would be in the relative vacuum of space where mass isn't relative because it is weightless at standstill and only gains mass in motion
BUT, if you accelerated up to lightspeed by continual thrust bursts of lets say 1000 mph, each time you thrust you are still only thrusting at 1000 mph and it is the accumulated speed that eventually breaks the speed of light but your mass wouldn't be any different than it was when thrusting 1000 mph would it?

this is something that I have always wondered so if any of you have any insight into this enigmatic problem and can offer a solution or input feel free... otherwise I am only talking at you and that would make you all a duh mass