So what I see problem with Nicehash and Windows is that Nichash is often trying to mine something that is optimized very bad on my system or overc. Tho I have not used Nicehash for some time, maybe this has been changed? If I want to use only mining software I have optimized, only coins and pools I have tested - what are my options? It also includes switching GPU settings, core speed, voltage etc. I dont think that Windows can do it easily.
From other side - I could get some benefit using only Claymore and mining only Ethash algos - also there are a lot of variations with income, etc/eth are swapping palces all the time and new athash coins are on the market.
I would like to sell everyday income and receive BTC.
What would you suggest for me to test? What servcies I should consider to use?
You do not mention how many and what type of GPUs you are using, but many miners with 6 to 10 GPUs per rig are using Windows. Most of the issues you describe are based only on the inability of the current version of the NiceHash software to apply separate overclock profiles for each algorithm. There are other algorithm switching programs written for Windows that will let you do most of what you described.
For example, my software, Hash Auger https://hashauger.com allows you to apply custom OC settings (GPU clock, memory clock, power limit and temp limit) per algorithm and GPU. You can also set custom settings like intensity and manual difficulty for the mining programs that support those parameters. You can enable specific pools, including Nicehash, and adjust a number of the price and hash rate factors used by the algorithm switcher. Similarly, you can disable individual algorithms on each pool and mine any number of individual coins instead of auto-exchanging to a single coin.