Modding Questions

Hello, I really appreciate the hard work the programmers have went through to make the game more fun for the general community. I have been toying around with making new cards and have stumbled upon a couple of things that I would like to know.
1. For the counter registration, do I HAVE to use an already built-in counter or can I create a new one? if I can, how can I add attributes to it. If not, can I for example use a blood counter, then cause every blood counter to add +3/+3 on the same creature? if so, can someone please show me how do I code that?
2.I have been trying to use the OR filter that uses card names, but It was to no avail. How would I code a filter to look for a card names "Soldier A" OR "Soldier B"? I tried but failed.
3.Is there a possibility to add a custom card subtype?
4.Regarding leveling, how to code a characteristic being added once a specific level has been reached? for example reaching lvl 3 and on, creature would have the intimidate ability.
Thanks in advance.
1. For the counter registration, do I HAVE to use an already built-in counter or can I create a new one? if I can, how can I add attributes to it. If not, can I for example use a blood counter, then cause every blood counter to add +3/+3 on the same creature? if so, can someone please show me how do I code that?
2.I have been trying to use the OR filter that uses card names, but It was to no avail. How would I code a filter to look for a card names "Soldier A" OR "Soldier B"? I tried but failed.
3.Is there a possibility to add a custom card subtype?
4.Regarding leveling, how to code a characteristic being added once a specific level has been reached? for example reaching lvl 3 and on, creature would have the intimidate ability.
Thanks in advance.