Having bored hundreds of bearing seats for the repair of electric motors, I can give you a guideline in how the fits feel: if the bearing race and housing or shaft are exactly the same size, this will give a light press fit. Typically, a shaft is left .0005" oversize and the bearing can be heated (carefully) on a waffle iron (but use the flat side of the plates ), then assembly must be done quickly and accurately. We use exactly the same interference spec no matter what size bearing it is, perhaps a bit less for a tiny bearing like yours.
For housing fits, we strive for a hand made "push fit". This is in the range of .0003" to .0005" clearance. Again, if they are exactly the same size, it is considered tight, but not harmful. It's just a real b!tch to assemble or take apart when they are that tight. The motor rewinders themselves will salvage a housing (instead of bringing it in for machining) if it is non-critical and has maybe .001 to .0015 clearance. They use loctite on it (but only one bearing can be loctited, the other must float, hence the need for the hand-made push fit).
Timken tapered roller bearings are a different story: these can have very heavy interference on the races, but that is because the bearing preload adjustment is possible after assembly.
You know your bearing is much too tight a fit if it suddenly feels like its a bit gritty when you roll it over after assembly. If you're sensitive and have lots of experience, you can feel a ball bearing get stiffer to roll when you've reduced the internal clearance with too much interference.
Tight fits tend to score the housings/shafts too, when assembling or disassembling. So if you do achieve a tight fit, be sure to lubricate the surfaces before assembly. Aluminum is especially bad for scoring when tight fits are used.
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)