A lot of questions there, but I'll try to answer SOME:
1). Don't know.
2). 2 minutes for the the ADSL light to go solid is abnormally long. All ADSL/BB connections are affected by local contention ratios (the number of people trying to connect). But NOT to the extent that you cannot connect at all.
3). I have a Sagem BB modem and it also shows as dial-up. This is perfectly normal (albeit a little odd) for BB modems. Don't worry about it.
4). Yes, delete all other connections except your current one. They MAY be causing some conflicts.
5). You don't say what speed you are subscribing to but you need to tell us what that 355 is. Is is KB/sec (kilobytes per second) or kbps (kilobits per second)?