I've noticed alot of new vegas editor IDs start with numerals. Doing so in Oblivion would cause issues with the objects when used in scripts. Is it now alright to use them in the GECK?

Not sure what you mean by "editor id". Do you mean the 8 digit hex "form id" like 0100abcd? These almost always start with numbers, at least until you have over 159 mods loaded.

It's still not recommended and people are having problems when they do so, especially if they are trying to use reference notation, like 00ReferenceName.VariableName

An example of an Editor ID is 188Alexander, it's FormID is 000E604F