The wife and I will be doing a one month backpack across Europe next summer and I had a question regarding the Eurail system. I was looking at the 1 month Eurail Global Pass (First Class is the only option) and figured it would be a good option since we will most likely be visiting at least 6 countries. However I was looking at train "tickets and schedules" on raileurope.com to determine travel time between certain locations and I noticed even if you have a pass it seems you have to pay a reservation fee on some lines.

Example:
London to Paris is over $200 even with the rail pass? That just doesn't seem right. I could book a flight on EasyJet.com for the same price probably. Do you only have to pay it if you make reservations or is it the same if you just show up and use your pass to catch some random destination?

I noticed other rails, like in Belgium and Netherlands don't charge anything for reservations.

Also since we will be going in June or July I imagine that is peak tourist time. Would it be wise to make reservations. From what I gather a Eurail Pass doesn't guarantee any seats. I don't know how often the various trains would be all booked during that season. I'd hate to sit somewhere for hours or even a day waiting to catch an opening.

$100/day per person sound like a reasonable budget in Europe? I'd rather budget way to much than not enough. Also, I know some places are a lot cheaper (Prague) than others (London). I plan on mostly utilizing hostels mainly, but I'm sure they won't be easy to get into that time of the year. We will both be carrying just a backpack with a few changes of clothes and other necessities.

Right now I'm mainly focusing on these locations:
France - Paris
Belgium - Brussels & Brugge
Netherlands - Amsterdam (DUH!)
Germany - Berlin, Mannheim (Friend stationed there), and maybe Munich
Switzerland - Lauterbrunnen Valley
Czech Republic - Prague
Italy - Cinque Terra, Rome, Venice, and maybe Vienna

Of course I'll be in UK as well since we will be flying and out of London. Spain would be a bonus, but due to time I may not have time to even get to everything on my list. Maybe I'll make it a 6 week trip instead of 4. I'd actually like to make it not planned out, but there are so many things I want to see (mainly Brugge, Amsterdam, Laterbrunnen Valley, Cinque Terra, Venice & Rome) and so little time.