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:

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> 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. 
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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: 
While I agree with the technical points that Nathaniel and Dale make, in that it does soften the tone of what is said, I don't think it is something that should immediately be avoided. 

To me that is akin to telling a carpenter to avoid using a chisel. 

I imagine a carpenter spends a good deal of time learning how to efficiently use a chisel. I'm sure they understand subtle differences in use in ways that we simply wouldn't notice. But we are capable of seeing the result. 

As a writer we have a rather different set of tools at our disposal. We have nuance, timing and metaphor, to name a few. A good writer understands the difference between 'So, this is my opinion!' and 'This is my opinion?' Both will be equally persuasive when used for the right point towards the right audience. 

As a writer it is your job to get a feel for those words, to understand which is the most appropriate for the piece you're writing. It takes a good deal of time to learn that skill. But personally, that is what I find so fascinating about writing...
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: 

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> This was founded. So people came. 
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is slightly less powerful than 

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> This was founded. People came.
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It has to do with the order of the words and such.