Question: I find myself using these words *all the time*. 

Now (<-- there's one!), to be clear the context I'm using them is in conversational style writing, on social commentary, or in forum posts like these. It's not formal academic writing, and it's not story telling. (In a fictional story, these words would be perfectly appropriate if used by a character). 

Here's an example where I've used it recently:

> 
> Point four, I think it is realistic that people would have this interpretation. **So** on this point I'll just stress that this blog post is not intended to be malicious or make anyone feel bad. It's more an interesting exploration of social interaction and how best react and navigate it. 
> 
> 
> 

My question is - is this actually an effective writing style, in the sense of being easy to read and persuasive, and if not, how do I get around it?

Answer: 
Dialog in writing is not the same as dialog in writing between two people. Usually the dialog is shorter. However, it is possible that to convey a specific character's attitude "filler" words like "so" can and should be used. I am sure that there are other reasons.

However, I find myself using them much too often in dialog and go back and delete them. Even for a character that uses filler words, I use them much less than they would be used in real life. I try to have only one character in a dialog use such words.

We are writers, and words are our tools. Each word should have an importance in our writing or it can be removed. Just be sure that the fillers that you use add to the writing rather than distract from it. This is very subjective.
Filler words can help you reach a higher word count, but if you want to be more concise, delete them. I find that filler words can help in rough drafts, but in final drafts, they sometimes detract from the power of the sentence. 

For example: 

> 
> This was founded. So people came. 
> 
> 
> 

is slightly less powerful than 

> 
> This was founded. People came.
> 
> 
> 

It has to do with the order of the words and such.