I see 1st level characters still as Apprentices still, especially with casters. Casters aren't going to study magic to years to learn a few spells and then take off. For one, where are they going to learn their spells after that? Apprenticeship lasts to level 3-5.
At the end of the apprenticeship (for any profession/craft), the character should know the basics of his profession. Not necessarily every every aspect, but at least the basics.
I think that this equates well with first level.
Now, the first 3-5 levels could be termed as being more of the "Journeyman" years of training (i.e. Advanced Apprenticeship??). Where the character goes out, practices his craft, and returns for further and more advanced training.
For non-adventuring crafts/professions, these Journeyman year are likely spent with their teacher/master, but with ever greater amounts of responsibility.
In the game, Harn, one of the aspects that I always found interesting was that once apprenticeship was complete, those young mages were forced to leave the chantry (i.e. the guild) to travel the world for a year and a day. Once that time was up, they had to return, and present the chantry with a new spell and a magic item that they had crafted. A way of showing that they were ready to move on to the next level of advancement (i.e. access to the guild's libraries, etc.. allowing them to study and learn more spells)
In RM, both as a player and a GM, I always did something similar. RM doesn't have spell books, not in the way that D&D does. I always had spell users keep spell books, but their books are essentially all of the notes and things that they learned during their apprenticeship. This way, these "spell books" become their study guides" for further development of their base lists as they travel and progress. As they travel and visit other places, they can visit other mage guilds, and if given access to their libraries, glean new information to add to their spell books (i.e. the stuff needed to advance in other spell lists that they had learned.).
In other words, the spell books contained the notes for base lists and any other lists that the character learned so that they could advance in those spell lists whenever they went up levels. Base lists were the only lists that did not have to be known to be entered in the book. (i.e. a Magician would have the notes needed to learn Ice Law even if he waited until he was 5th level before learning it).
As for making 1st level characters stronger, the only thing really needed is basically what we did for RMX, up hits a little bit, and up Power Points a little bit. (and perhaps get rid of multipliers, and intro a way of recovering PP faster than sleeping 8 hours).
Anything else added should be balanced through removing DPs...
Just a few thoughts...