Samsung has a Security selection in your settings. That's where you check the "Unknown Sources" box. Then you tap the link Amazon sends you in the email when you've asked to add a device. The email Amazon sends explains everything.
I think the Galaxy Note 10.1 is probably better known for designing and drawing with its note format and S pen stylus. The Note has a more powerful CPU with a 1.4 Ghz Quad-Core Processor compared to a 1.0 Ghz Dual Processor. It has better cameras (more megapixels). You can also purchase the Note with more internal memory than 16 GB if you want to pay extra. A notable difference is in the price: $299 versus $449 right now on Amazon. You might also want to go to Samsung.com and compare the two models next to each other.
You will need to download an older version of Adobe Flash Player. As of 8/15/12, Adobe no longer supports other mobile devices with their new version. An older version is a work around, but works just fine.
Although I haven't tried comics I've read in other Questions that they work great. I think the browser does a great job; fast and efficient. I would assume the "big guns" can do more, but you'll certainly pay a lot more. For the money, this is the best choice I can think of. You should know, however, that you can't load apps on the micro-SD card, only pictures, music, etc.
When you go to Adobe.com, you want to download a version of Flash from the Archives for Android. The current version of Flash is not supported on mobile devices. Make sure you've gone into your tablet settings and enabled third party apps before starting.
What is long? An hour? My tablet doesn't take very long to charge or to drain the battery. I just put it on the charger every night when I sleep. If yours is not charging fast enough you might want to buy a new charger first and then if it still takes too long contact samsung.