I'm wondering if it is possible to change the meta description of a page on your site at any time without it affecting rankings on google? Is it only changing how my SERP looks? Or could bad things happen to changing your meta description? Appreciate all opinions on this one, thank you guys!

Hey guys, I'm having some issues with my wordpress blog, and I believe SEO plugin by Yoast could be the one causing it. I have set a title for my wordpress blog, and a tagline. This was set in dashboard > settings > general Under "titles and metas" > home in the plugin it says, title: %%sitename%% %%page%% %%sep%% %%sitedesc%%, and meta description is blank. The reports on seomoz says my title is title+meta description - making it to long (to many characters). What could be the issue here? Thanks in advance!

Couldn't find the answer to my question anywhere so I'll give it a try here. If you have a site called www.example.com, and then want to add a keyword to this site, like this: www.example.com/keyword How do you add a keyword to your url like this? Without making the URL with the keyword your "main" URL, meaning you don't have to enter the keyworded URL to get to the homepage (www.example.com), and still rank better on the keyword put in the url. I'm a bit confused on the subject, would love for someone to help me understand! Thanks.