1. Are you talking about the just-released new ICS mp5 model, or the older one?
2. Do not watch 14 year old kids video "reviews" on youtube.
3. Yes, Mach1airsoft is good.
4. Quick google search: ics mp5 review - Google Search
5. Yes, ICS is a good, innovative brand overall. IIRC the old ICS MP5 is not a split design though.