- Is this set I mentioned above violating any rules of this forum
could be considered as violation of any copyrights?
From looking at the product listing, I don't see anything that could possibly be copyrighted. The only way there could be a copyright violation is if it came with a booklet that contained content copied from Arduino's starter kit book, which is under copyright. However, there is no indication that it comes with any sort of instructions at all.
It's more common for there to be trademark violations (though Arduino has gotten much more active in dealing with trademark violators in recent years, so it's less common now). The common trademark violation is people selling boards that have the Arduino trademark on them, even though they were not made by Arduino or someone with a license to use Arduino's trademark. That is a counterfeit product. From the picture of the board in the product listing, I don't see Arduino's trademark. However, I do see the silkscreen on the Mega derivative claims "MADE IN ITALY", which is an absolute lie. Everyone knows that board was made in China. That gives you an idea of the ethics of the people who made it.
2. If I decide to buy something like this, will anyone in this forum will be able to help me, considering the fact is not from official channel of sale?
Yeah, no problem. The kit is all the common modules and parts. It's actually more likely that forum members will have them on hand than that they'd have an official Arduino Starter Kit on hand. Of course, if you're hoping to get official support for that thing, good luck, whereas if you buy an official Arduino Starter Kit you will be welcome to contact Arduino Store Support with any questions or problems you have.
There are one or two forum members who will gripe if you ask questions about a clone Arduino board like that Mega, but the majority of us will help anyone.
Of course, it is very important to support Arduino. The IDE an many of the libraries you will be using with that kit are provided as free open source by Arduino. You will be regularly using the documentation written by Arduino to learn. Arduino pays a team of professional developers and technical writers to work full time on improving and expanding all of these resources. That is all dependent on people buying official Arduino products or making donations. Despite all this work being open source, which anyone can contribute to, I guarantee that Banggood will never do a single thing for the Arduino project, even though they greatly benefit from it.
3. Is a good idea to buy something cheap
I would go with the less expensive boards to get started with. The reason is that it's fairly certain that you're going to have a "magic smoke" incident along the way and destroy it. That's just an inevitable part of the learning process. If you do that with the Mega, then it's going to cost you more to replace. If you do it with the Uno, then it's less painful and you'll feel more free to take risks and experiment. The Mega does have a lot more pins and memory than the Uno, but you can do a lot with the Uno, then get a Mega once you have gone through the initial learning process and are doing a project that actually requires more pins or memory.
it's something completely new for me and maybe I will not achieve anything at all and it will be just waste of money - and if it will be, in my opinion it's better to spend less than more for this.
The thing is, compared to what it would have cost you to get into working with microcontrollers a couple of decades ago, this cost is nothing. The potential learning and fun you can get from an Arduino board is worth so much more than the cost of the board. That said, I definitely wouldn't recommend getting two starter kits. Just get one. That will give you plenty enough to keep you busy. My preference is to buy the specific parts I need for projects, rather than having a random selection of parts forced on me by a kit. When it comes to these Chinese modules, there isn't even any cost savings from buying a kit vs. just buying individual modules. That said, a kit might be a good thing for a beginner who doesn't really know what they want to do and just wants to play around with Arduino and learn things. For that purpose, an LED matrix is just as good as an LCD.