UO is a great game for a casual gamer imo, i played UO from 98-2003 then brain farted and went to play lineage II for 2 years....the grinding made it more like work than fun and if you missed a week you were behind everyone....but i am back to UO for the last 6 months or so and loving it they have added so much content...i will try to answer your questions best i can

1 you might be overwhelmed but more by people trying to help you, you really should have no problem finding help when you need it and places to hunt/train without interfernce, Felluca is the only place non consentual pvp is allowed so you shouldnt have to worry about pks, as a young play you can't even go there for 40 game hours(ways around that though if you need the pk excitment) yes you can start and still make it to the top of the food chain in UO nps

2 time spent on leveling a char depends on what char you create a warrior type char are usually easier to level/equip when you are a beginer should take you a few weeks to get to uber dragon slayer ;p , but if you want to be a bard or tamer it will take you a lot of time training but worth it imo....good thing about UO is you can actually have fun while playing, it isn't such a grind grind grind game

3 economy is a little tricky....as for making gold killing monsters is the easy way for a beginer but then once you accquire items thru game play or off other people you can set up a vendor or become a mercant(banksitter/spamer) affording the top armor in the game will take a while but you can have great armor in no time

4 crafting is fairly easy just monotinuos and takes some time to gather resouces, crafting can be profitable but i wouldn't start a crafter as my first char....

5 housing on most shards is very affordable and if you saved hard you could afford to place a small house in as little as a week of casual play...housing is one of the greatest features in UO imo

6 ships are good for fishing and can sail to most lands that way although there are alot fast means of travel...ships really dont affect the game much but there are differnt types but sadly they look pretty simulair

7 yes but i am not sure on which is which maybe someone else can help on this

8 i hated lineageII because i was forced to group, UO is great because you can solo almost everythng in the game,gear/items/time permited but still do things in groups

9 UO is a very very in depth game imo but it is still simple enough to pick up, play and have a blast for a causual gamer

10 no death penalty but you will be a ghost and have to find a healer to rez you then go back to gather your belongings

hopefully this helps some, i answered a little more in depth the first time but then when i went to preview the post it booted me....grrr