This just isn't true at all.
Poland, Muscovy/Novgorod, France, England, Castille, Milan, Ottomans, and so on are better choices if you just want to blob. Austria played properly needs to use Personal Unions or it will never catch up to France in a reasonable time span.
Poland, Moscowy, Novgorod all put him in Eastern Tech, and throw him against the Golden Horde. Ditto with the Ottomans, save for slightly better tech and the Timurids instead of the Golden Horde. I would say that is far less friendly to the comparitively comfortable position that Austria has.
Milan and Castille are both good options, with the ability to form Italy and Spain (respectively) easily and early.
Edit: Guess I should probably elaborate on this a bit.
I should, too. I am not saying that Austria is the best nation for a learning player, but that it would be a fine nation if you consider the player's circumstances (a game of friends). I am sure his buddies will be willing to teach him in-game.
Were he joining a MP game set-up on the forums with players of varying skill levels, I would certainly persuade him to take a different nation.
The HRE is both a great advantage and an annoyance to be in. Being the emperor gives absurd benefits (which Austria wants and needs), and the PU coring mechanics are great too (as are imperial integrity and such). Leaving the empire basically makes you into a smaller France/Turkey/etc with worse CBs, and blobbing normally while remaining in it gives you too much infamy to be the emperor (and the +0.25infamy/province from unlawful territory kills you pretty quickly). PUs are a natural solution since they're quick, easy, give you cores, give you massive prestige which you can use to improve your SoI, and don't cost infamy.
It should be mentioned that the Imperial Throne can be snatched away from AI Bohemia pretty easily.
England fighting France, especially in such a small game, makes little sense unless Burgundy is played.
AI Burgundy goes to war with France pretty regularly. The chances only increase with the more unique missions that the Burgundy AI has completed. I could see England jumping in if he considers France a threat (especially if France is the most experienced of the group).
If it won't be played optimally then fine, but in that case you might as well say "do whatever you want". Austria needs to expand with PUs if it wants to be effective.
Oh, don't pull that crap. If he's playing with friends for a bit of fun, I bet the furthest thing from his mind is an optimal Austria build (ESPECIALLY if he is new). He wants to be Austria. Let him. Don't discourage him - be helpful and give him tips. The number of negative nancies in this thread is just insane. You're all thinking in terms of "Multiplayer game with random forumites who have played the game for hundreds of hours," but that is clearly not the situation the OP describes.