Does it make a difference??

I'm currently in chapter 1. Just met a ranger and kicked a bard out of my party.

Yesterday I installed patches and TOTSC. Would this change any quests (done so fare), items or the story if I started all over?

I noticed a few minor changes. Got 2 extra hitpoints and now I need to identify a special item.

How can I see which quests I've done when they stay on the same page in the quest book?

Thanks for the help.

[Hayashi]

ToSC doesn't subtract anything from the original BG1. It simply adds a new area to the map which is the starting point for 3 new quests that you wouldn't otherwise get, including the (in)famous Durlag's Tower. These quests take place in all new areas too, except for one or two locations in the city of Baldur's Gate which you will need to visit.
The other thing that ToSC does is to raise the exp cap from 89,000 to 161,000.
Unfortunately the journal is BG1 is not as good as the one in BG2. All quests, whether completed or not, are listed on the same page. Updates to quests, such as when you finsih one, are listed on the same page and iirc the original quest journal entry is not deleted either. It gets very tedious after a while scrolling through trying to see what has been done and what is still outstanding.

[SixOfSpades]

In order to visit the areas added with ToSC, you may or may not need to run the program called MCONVERT in your BG directory--it depends on whether or not you've done the full install of ToSC.