That's a horrible thing to tell people. You are selling a promise of a "shitload of profit" on a highly volatile financial experiment. In 5 -15 years bitcoin *might* have an exchange rate significantly higher than today, but it also might be significantly lower than it is today. If you tell someone that they WILL "make shitload of profit", and then they don't, are you going to compensate them for the profit that you promised them?
I don't understand the question. What do you mean by "what if"? CPU's and GPU's DO get more developed and become better and better and faster over the years. In the early 1980's I had a desktop computer with a 1 megahertz CPU. Today you can purchase consumer grade computers with multiple cores operating in excess of 3.5 gigahertz. That's 3500 times faster! In the beginning of bitcoin, mining was only done with CPU. Then someone figured out how to mine even faster with GPU. Then someone figured out how to mine even faster with FGPA. Then someone built a custom designed circuit specifically for the application of bitcoin mining (ASIC). This was even faster than FGPA. Faster and faster custom designed circuits are being created. The more efficient bitcoin mining becomes, the more secure its blockchain is.
No. It would just increase the security of the the bitcoin blockchain. Faster processing of hashes means more hashes per second calculated by the mining participants. This just increases the number of hashes per second an attacker would need to calculate in order to control a substantial percentage of the global hash power.
No. That's not "logical" at all. The bitcoin difficulty is adjusted every 2016 blocks to keep the average time between blocks close to 10 minutes. If equipment can calculate more hashes per second, then the difficulty is increased.
You don't know what you are talking about.