I don't think the light will be too intense with the frosted covers. Less than traditional bulbs and comparable to fluorescent tubes with a diffuser. Your eyes are well adapted to ignore bright light sources above eye-level.
There are two issues with heatsinking of LED strips, one is the transfer of heat from the LED itself out of the SMD, and the other where the heat goes once it is outside the SMD. 5050 SMDs are a relatively old design that is not especially well-heatsinked internally. It contains three individual diodes, essentially the same as the diodes in a 3528 SMD. When run in RGB mode, essentially with only one diode out of the three running continuously, the heatsinking is up to the job, but with all the diodes running continuously as in a white-light version they are quite stressed. Also as a fairly high-power design, a mounting on wood or plastic isn't sufficient to properly shift the heat away from the strip. Mounted on aluminium they should be OK, especially if it is a quality product. Nevertheless, I'd recommend looking for a newer design such as a 5630/5730 SMD if you really really want something that bright.
Having said all that, I think a 5050 strip will be considerably brighter than you need. It would give something approaching 1,000 lumens/m which would be a total of 5,000 for your room. If you think the room would need four traditional 100W bulbs to be properly lit, then go for it. Otherwise consider a less bright strip.
In the same vein, consider task lighting in addition to the main room lighting. Trying to provide good lighting on the work surfaces using only ceiling lights just doesn't work, not least because you're always creating shade on the working area. There really is no substitute for dedicated task lighting which you can then have at levels which would be glaring for the whole room. A good rule of thumb is 500-1,000 lux for kitchen task lighting and then only 100-200 for ambient lighting. That would mean you only need something like 1,200-2,400 lumens from your ceiling strips.