Migone1,
Just my 2 cents. Shared is fine on a server optimized for Dolphin. Some hosts have a difficult time handling Dolphin with shared. I have been with through two hosts since opening the site in March. First two, could not handle my site with ten members online, not using chat, just the forums. I am now with Zarconia for two months without issues. As your membership grows of course you will need to upgrade, but you should be earning enough to offset the costs. If not, then that is where you need to concentrate, because if you were generating income you would not mind to upgrade the server.
Here's some advice for spam. I had a problem the first week. I put one human question on the join form, and banned everyone from China which eliminated 98% of spam from entering the site. At least the robot spam, I have very tiny amount of human spam, but I approve every Applicant by looking at their account before activating. Still the only way to be 99.9% is to charge a fee to enter the site. Suggestion, you may consider blocking non members from entering certain areas. For example, I can look at your members list. One option is go into Admin>Builders>Navigation menu> click on the top block and restrict to members only the areas that you wish to restrict. Some spammers will stop hitting the site if they cannot get any information.
SSL certificates, there are different types, Look at Namecheap.com for information. Not saying that they are the place to buy, but you will get educated on the different types and be better prepared.
Hope this helps
Vunderba..... Challenge Yourself to be the Best...... Hosting from Zarconia.net