Theme update help and info

I’ve build my website using Hershel Yoga template. But customized it to the T.
You can see it at

I have a few questions about the update, as I’m not a developer or a web designer and I don’t know enough about this.

1- Do I need to update it?
2- If yes, why?
3- What happens if I don’t, over the years?
4- Could things in my customized template go wrong or need to be fixed, if I did updated to the newer version? Could the update mess things up?
5- Why is there not an update button, but only the full theme download?
6- Is it gonna be a huge and complicated job?

I would really appreciate some guidance.

Thank you very much

1,2. It depends upon what is included in the update. For example, if there is a security issue in the theme which could possible lead to hack of your site then it is recommended that you update.
3. On one of my site, I ignored the 2015 revolution slider update which was a security update. And after some time the site was corrupted with malicious code and the domain was blacklisted and I had to waste a lot of time and effort to get things back on track.
4. Yes, if you made changes directly in the code of the theme. If you followed the WordPress way of code, like running custom functions on actions and hooks, then you can simply copy your changes and apply them later on as they’re almost independent of theme.
5. Depends on the theme, try installing the Envato market plugin for updates.
6. It could be, depending upon the customisations that you have done.

If you’re reluctant, try contacting the author of the product about the update and whether it is necessary to update or not.

Thank you so much for that, it’s helpful.
The website got live at the beginning of this year and I have already been hacked with fishing.
So may be… but It’s definitely very customized i think.
How do I contact the author? How do I find the author?
Sorry I"m really not practiced at this.
Thank you

In your themeforest account, in the Downloads section you will see your theme. Click on it and then go to the Support tab.

If your support expired than you may need to buy some more, otherwise just hit Contact Author.