Drupal performance on different hosting - Frustrated

I am very concerned by Drupal performance as it directly affects the productivity of people contributing to the content
(It is a Content Management System, isn't it?)

Beside "productivity", ie the time it takes to view, create or updtate content elements, reactivity is a key factor to keep contributor acting. A lazy system will discourge them to collaborate.

So I am mainly - only - interested in improving performance for logged in users. Drupal basic caching does not help.

This introduction is for explaining my furious search for decent performances, I mean getting a screen poping for normal contributions - < 1" - , fast enough for more demanding administrative tasks.

Having started on a shared hosting in US (I live in France), I was said that I should go for dedicated of VPS.
So I opted for dedicated-like (Real Private server, sharing iSCSCI drives), then fully dedicated,
In the meantime, I gave a try "high performance" shared hosting. I currently run the same web site on 3 different environments:

1) "Normal" Mutual hosting : www.bluehost.com (US, Kenosha)
2) Dedicated hoting: OVH 2XL http://www.kimsufi.com/ (FR, 200 Km) Intel E2180 64bits 2*2GHz, RAM 2GO
3) "High performance" shared hosting : www.simplehelix.com (US, LA)

All are Xcache enabled

Bellow the best results I get from these very different configurations, as reported by Yslow and Devel

Value (1) is for calling a new node creation, ie node/add/stoty
Value (2) is for calling the "Block" page admin/build/block/list
Value (3) is for calling the simplest page on the site: plain text, no views.
Value (4) is for calling the "Module list" page admin/build/modules/list

The database has 70K record, 12 Mb data, 141 tables. It is sane.
On the dedicated hosting, I tuned MySQL the best I could

Bluehost OVH Kimsufi SimpleHelix
(1) (2) (3) (4) (1) (2) (3) (4) (1) (2) (3) (4)
Yslow with/ devel S 3 3,5 2 10,8 2,5 4,3 2,2 7,5 2,4 3,5 1,8 6,8
Yslow with devel S 7 4 4,1 111* 5 4,2 3,7 54* 4,7 5,2 2,9 42*
# of queries 365 304 283 5831 609 560 522 6171 524 528 510 5329
Queries ms 140 121 101 2533 260 250 231 2463 164 180 139 1923
Page ms 900 1200 700 11019 1085 1175 992 6163 735 900 424 4872
Slowest query ms 31 4,3 4,3 69 2,7 2,65 2,7 49 4,3 4,3 4,3 69
Fastes query ms 0,1 0,1 0,1 0,1 0,16 0,13 0,15 0,16 0,06 0,05 0,05 0,05

Pricing/month 8$ 40$ 20$

Conclusions:
- whatever power is involved, Drupal is SLOOOOOOOOOOOOOOOW
- Dedicated hosting is REAAAALy cumbersome, for little improvement

1) How is it possible that Drupal processes so many queries (> always more than 500, somethimes 10*) - Is this normal?
2) Bluehost always reports less queries, sometimes 50% less. Where could this come from???
3) Are these numbers normal for Drupal, so I am simply exceptionnally demanding? (see introduction)
4) Should I try to increase the power, going to a 100$/month hosting for 4*3GHz /8Go to get acceptable performances?
5) I installed Cache Router, but never got it work, nor being able to to get any support. Could it improve things?
6) Any idea to improve this situation?

Thank you for sharing your opinion and giving any advice?