Yes, you can use you Joomla, no problem at all than using the Wordpress. WP is just really badly written, It's the number one cause of weird errors, suspensions, and even Phishing bans. (usually when the hackers set up phishing on your account) A 500 error with WP is almost always due to installing defective, bloated, or simply too many plugins. It’s really terrible and it throws in a lot of errors and also a lot of hacks. We have a lot of users successfully installing Joomla on their sites and that is recommended.