Are there any secure libraries in C/C++ or Python that can allow to get unconfirmed transactions, get block templates, create a block header, help check the structure of block, publish the block after its mined, see if it was mined successfully and receive the mining reward if the mining was successful in a preexisting online wallet or local wallet.
From whatever I am reading we need bitcoin core but it requires 400 GB download (bandwidth issue not storage). And I am failing to understand why we absolutely need it if we are just mining and publishing the whole block. Why can't we use libraries that use RPCs or have the data (like format etc) in them as we don't need a full client, block list or node for it. These tasks seem relatively simpler.
The mining of the header (the core of it as I understand is guessing the nonce) could be done separately by the user as solo (we don't need to worry about it). The rest of the process is what we are concerned about.
My environment is windows 32 bit.
I am new to bitcoins thus need some help as I am lost on this. P.S. I am not trying to make profit and under no illusion that the problem is easy. So we don't need to worry about that. Just that failing to find the appropriate libraries/SW.