Did you notice that Animated Object has both a race and a class? Also, the animated object would have to be Awakened because PCs require an intelligence score.
I'm also not sure how Os will feel about a generic Awakened prestige class where there are at least ten Awakened (xxx) classes already created.
Let me list some problems. From size modifiers for being Tiny, they have -8 Strength, which, with the -2 racial, menas they have
0 strength on average, and get +4 Dex, with another +2 from racial. And have 50 ft. move if they are bipedal from the race, regardless of size, at the "cost" of being able to be tripped. As opposed to 40 ft. move when they can't be tripped, which is still faster than the typical party member. Wheels give 80 ft. move at the low cost of not getting to use Climb or Jump, rendered irrelevant by being able to grab Flight at 1st level and have proper flight at 3 HD. 40 ft. speed Clumsy flight, due to being half land speed, meaning that they are
still moving faster than the rest of the party while flying. Or swimming or climbing, if they pick one of the other options.
At 3rd level, they can carry the entire party by having the Box option and taking all the Growth choices they get for being level three. One member can use them as a mount, the other two can ride inside with cover and be able to fight back. Oh, and Construct traits give Large Constructs 30 extra HP, meaning average HP for this creature at
ECL 3 is 56 HP. 10 from maxed first HD, 11 for 2d10 average, 30 for Large Construct. Oh, wait, there's another three HP for Objective Object, meaning it's 5
9 HP at ECL three. With the ability to have two Medium-sized party members inside with cover and able to take advantage of the bloated move speed to have a battle bus that can fly faster than they can walk. Which, due to Strength and size modifiers, is probably dealing upwards of 20 damage per attack itself. Let's see... +8 Str size modifier, +5 Str from the class, -2 from the race, which means +11 Strength. x1.5 for Slam means 16.5 and then 3.5 for average roll, meaning that it actually is dealing 20 damage on average. At ECL 3. While having 59 HP, on average.
So... I do believe that it needs an overhaul.
In regards to a generic Awakened class, it can be useful for someone who wants to use a mindless creature that doesn't have one of these classes, or for people who want to use only a small subsection of the classes and the DM is picking them based on having a rebalanced LA to handle the ECL problems, like a certain thread series by a user with the name of Inevitability over on Giant in the Playground. Or they want to turn their skeletal Orcs into decently intelligent minions, which the Awaken Undead spell doesn't allow by capping at the racial average.
Semi-generic classes for certain common changes work out fairly well for this purpose. A one-size-fits-all Awaken PRC wouldn't work out well, it's too general, but one for each commonly-eligible creature type, as in Ooze, Vermin, Construct, Undead, Animal and Plant, would certainly make things less crazy and more open. Slight subdivisions through AFCs allows you to tune it a bit better.