Will changing my site theme and content hurt the ranking?

I have a money site with 3 pages that is ranking for a few keywords on page 1 and 2s. I used articles that i bought for $10 each but decided to change them to a more "personal" or more informative hand-written content.

1-Will these affects my ranking in a way that I have to "restart" the building of backlinks and stuffs?

2-What if i also change my theme?

3-Should I do this in one shot or slowly change the articles and then move on to the new theme?

Changing the theme usually will not hurt your rankings unless you go for a theme that sucks from onpage SEO perspective.

Rewriting the article in a more personal style should be fine as long as you do not change the content (use the same LSI keywords & same kw density) however I prefer not to touch articles anymore after I ranked them.

And also make sure you keep the same permalinks (or maybe use 301 redirects) because that will affect your backlinks.

Actually, you're asking two different questions.

You're asking whether your theme can impact your rankings.

You're also asking whether your content can impact your rankings.

The answer to your second question is actually quite obvious.

I hope you see it.

Content drives your rankings, so if you change your content in any material way, expect your rankings to be affected.

With that said, this doesn't necessarily mean that changes would produce a negative effect.

In some situations, if you change your content, this might actually improve your rankings.

As far as your first question goes, it all depends on the theme that you choose.

There are many WordPress themes out there and some of them are written in a very horrible way that they can actually impact how your website processes links
or presents information.

The net effect is you get less traffic from search engines.

You may want to do some research on a theme before buying it.

Usually, if a theme is notorious for killing search rankings, at least one person would write an angry blog post regarding that effect.

I wish you the best of luck.

Well, if you have your own company, and if you change your office look, it will maybe affect your workers productivity, and if you change your workers it will probably change your business position.

So, you need to think the same way with your website.

When you change the content google will notice the changes and re-evaluate the content.

When you change your theme you change your site structure and how your link juice flows.

You will not have to "start over" but it can shake things up in a good or bad way.

Changing your theme can make a difference to your rankings. This is because wordpress has lots of features and some of the themes include only a few of the features while others may include a lot of features. Some of the features may be part of the custom configuration of the theme and may require you to manually disable the feature. All these things do make a difference to the internal links and the anchor text pointing back to each page, which in turn impacts rankings.

If you really want to understand how wordpress features can adversely impact your rankings you should read phpbuilts post on authority site which also gives you details on over optimization with wordpress - http://www.blackhatworld.com/blackh...diot-proof-guide-authority-site-building.html