Deprecated - Performance and scalability

Hi all, looking for some help!

Basically I run a community site which has been up and growing for about 2 years now. Lately my site has been getting slower and slower, and frequently has periods lately where it doesn't respond at all, but then 1 minute later will be fine. I have upgraded my VPS numerous times and that has helped hold off the issue, but it seems my last resort is to upgrade to a fully dedicated server, but I wanted to see if my results were typical before going that far as that type of solution is quite a chunk of change.

Here are my server stats:
http://www.hostforweb.com/vps.html

HFWVPS-3
Guaranteed RAM 768+ MB
Guaranteed CPU 626.6+ Mhz

And here are my drupal stats:
1926 users
6370 nodes
120446 comments
7970 nodevote (used on blog nodes only)
139742 votingapi_vote
101194 votingapi_cache
3205 term_data
8328 term_node

Modules enabled:
actions, adsense, archive, basicevent, blog, captcha, comment, contact, event, feedback, freelinking, menu, nodevote, page, path, ping, poll, print, profile, quotes, search, story, taxonomy, throttle, tinymce, tracker, upload, urlfilter, views, views_rss, views_theme_wizard, views_ui, vote_up_down, voting_actions, votingapi

I find it annoying how on Drupal sites clicking on the back button is as slow as clicking on a link. (it should be instant since the page has already been loaded)

I noticed that there was a 'Pragma: no-cache' directive set in bootstrap.inc. I commented it out, and WOW, going backwards is almost instant. I'm sure this would have a huge performance impact since the page doesn't need to be completely regenerated. Users would also certainly notice a major speed improvement.

I use a lot of CCK and I think it is slowing my database server to much. I have read some pages and there they say to use innodb in order to save time. Should this changes apply to all database? just cck ones? ....

on the other hand, the use of innodb lets you use foreign keys, if I define nid, uid, etc.... in all the tables as foreign keys, should this speed things up?

any hint is appreciated,

Hi, I am having a bit of trouble with my screen reader Jaws For Windows. When I go into the settings page to change the site name and such it won't let me erase or edit within the form. When I installed 5.1 the cpanel of my host had the form right there for me to fill in all ready but I hand installed 4.7 because I needed mods that worked with 4.7 and not 5.1 Now I had to have a sighted person fill in the form for me. Is there something I can use, a mod I can install that will make the form fields more user friendly?

I'm trying to insert a simple form to my front page so that users can subscribe to my ConstantContact list. Code is below. Problem is that if any other button appears on the page (such as "Preview" or "Submit", etc), now all buttons link back to the "Go" button URL (http://www.constantcontact.com/safesubscribe.jsp). Curiously, the "Search" button does not seem to be affected. This occurs whether the code is hard-coded into the template page.tpl.php file or inserted via admin/block/add.

Hi all,