Well first of all this is an anti spyware forum, so all topics related should have to do with spy or malware
we can't start answering all the questions of all the problems or findings people need. There are specific forums for each sort of question, here : it's malware
For these kind of questions just type em in google and you will find thousands of answers and forums
1. IE is the most attacked browser in terms of malware, simply because it's used by >80% of the people. Mozilla and firefox are safer because they don'tcare to right malware code for it.
2. Try different browsers to cehck it, i don't think dlspeed in terms of kb would differ, but it's a known fact that IE8 is slower than alternative browsers in terms of opening web pages or internet window