First, regarding this question:
I was to make a base using water, sugar (6-7Kg roughly) and turbo yeast, then add my flavouring, to produce a drink similar to vodka or gin, would these still be classes [sic] as spirits, even at say 20-23%?
That is more of a legal question and is really outside of the scope of this site.
Now, whether you can technically do it is a different question altogether (ie, is it technically possibly to make a 20% - 23% beverage without distilling?)
tl;dr: Technically yes, but you really need to know what you're doing. See below.
If your goal is just "20%-23% alcoholic beverage," you can accomplish that without any form of distillation by using a rigorous nutrient and step-feeding schedule along with an alcohol-tolerant yeast with low nutrient requirements, like Lalvin EC-1118 or K1-V1116. It's definitely not easy, but it is technically possible. It would also likely require quite a bit of aging to be palatable, as you would be pushing yeast well past its tolerance, leading to lots of fusel alcohols and other off-flavors.
Now, depending 100% on the legality of this in your region, you could also look into "fractional freezing" (colloquially called "freeze distillation," even though you're not actually distilling anything)
Fractional freezing is a process used in process engineering and chemistry to separate substances with different melting points. It can be done by partial melting of a solid, for example in zone refining of silicon or metals, or by partial crystallization of a liquid, as in freeze distillation, also called normal freezing or progressive freezing.
This is the process that was originally used in creating applejack, and is used to some extent in creating ice beers such as an eisbock
Be careful though. Whereas distillation leaves impurities behind, fractional freezing concentrates them:
The danger of freeze distillation of alcoholic beverages, is that unlike heat distillation, where the methanol and other impurities can be separated from the finished product, freeze distillation does not remove them. Thus the ratio of impurities may be increased compared to the total volume of the beverage. This concentration may cause side effects to the drinker, leading to intense hangovers and a condition known as "apple palsy" (although this term has also simply been used to refer to intoxication, especially from applejack.)
This can be minimized or avoided if you have a clean fermentation free of fusels, have aged the fusels out of your beverage, or both.
Still, do not attempt the fractional freezing of a homebrewed alcoholic beverage without solid fermentation management techniques. Or if it's illegal in your country, I guess.