I made a fresh joomla install after the last one (the same website) I used to have 400 validation erros on the other one.. now I have none. I have reduce the size of images and other things.
Each time you add a 3rd party component or some type of functionality, some type of script is required to make it run.
Since you've set up your site the way you want it to be, you can't really 'fix' it.
The only way to do so is to have less 3rd party components running, you'd have to choose which ones you wanted to keep or get rid of the ones that are slowing the site down.
If you like it the way it is, then you have to sacrifice a bit of speed.
I have seyert and phoca gallery installed but Im not using that.. so if I remove that will be better for my final speed? this counts for plugins and modules too?