I do not really consider ¨kinda¨ as a real word, slang or otherwise.  It is similar to ¨ah,¨ ¨um,¨ or ¨ooh:  It is the way we write the sound of the words ¨kind of¨ because English speakers usually pronounce it as ¨kinda¨ instead of pronouncing it well.   Because of texting, it has become common for people to ¨write¨ in a very informal manner and use ¨words¨ that are not really standard words, but are things you hear in people´s speech all the time. 

My advice is to avoid writing ¨words¨ like ¨kinda,¨ ¨gotta,¨ ¨wanna,¨ ¨ur,¨ and ¨i¨ unless it is for poetry, lyrics, or a script for a play. It really is not that hard to spell them out and makes a much better impression. 

In terms of a sentence with, ¨I kinda want to...¨ it implies a small desire to do something, mixed feelings about doing something, or a desire that you are not proud of. So yes, I would say it is minimizing it.  

As others above have explained 'kinda' is just sloppy English. We take all kinds of short cuts when speaking and 'kinda' is just a fast way of saying 'kind of'. When writing, you should avoid these unless you are texting friends.

You may often see things like the following, but it is very far from 'proper' English:

Sup dude! U wanna go 2 da bar an get wasted? Ur buying!

It gets the point across, but also makes you look like you are somewhat uneducated or trying to look cool by using every slang, sloppy shortcut you can find.

"Kinda" seems totally uneducated to me.  The only place it seems "ok" is in dialogues where the author is imitating someone's speech.

I group it with gonna,  wanna, cuz, etc. 

I kinda want to go back outside - for me this sentence is something I would say as a 20 year old and most likely I would say 'I kinda (kind of) wanna (want to) go back outside'.  It's a mix between slang and abbreviation.  For example,  my nan wouldn't say kinda in the same way she would use abbreviations such as 'don't' instead of do not etc. but it is not the same as most slang as she would understand what I mean by saying kinda and it doesn't have an exclusive meaning in the same way that slang does.  It's slang in the sense that it is mostly used by a certain generation etc. but it is also an abbreviation as kinda has the same meaning of 'kind of' but that is not widely used by everyone in the population as I mentioned it's not something I have ever heard an older person say.  

So I would say when using 'kinda' it is a contraction of the words 'kind of' and also slang as it is not official in the English language and is mostly used by a younger generation when speaking to friends etc.