1. Yes, you must always sign into Origin, but you can make Origin remember your login, so you log in automatically when starting Origin.
2. The Ultimate Collection is a whole bunch of games, created over a time span of some fifteen years, so all of them have very different problems. So it might be handy to specify exactly which game you're talking about there.
3. Again, which game?
The basic way of getting the C&C games running on Origin is generally to disable the Origin In Game thing for all games in the collection (since they kind of hang/crash on startup if it's enabled), to install the unofficial patches for the first three games, and to install Bibber's fixed game launchers, which allow more options for launching the games and which fix some missing registry entries.
- For the first, open the game's properties in the Origin client, and check the "Disable Origin In Game" option. Do this for every game in the collection.
If the option is greyed out, this means you tried to launch the game, and due to the malfunction, Origin thinks it's still running. To fix that, either kill the game launcher in the Task Manager, or just restart your computer.
- For the second, this is where you find those unofficial patches:
C&C1: http://nyerguds.arsaneus-design.com/cnc95upd/cc95p106/
RA1: http://funkyfr3sh.cncnet.org/
TS: http://cnc-comm.com/community/index.php?topic=3438.0
- For the third, Bibber's fixed launchers can be found at http://bibber.eu/downloads/cnc-ultimate-collection-launchers/
Besides that, individual games might still need some tweaking in compatibility modes and such. See the sticky topics in this forum for more information on that.