We have rented homes from VRBO about 3 times down in the Anaheim area for our
Disneyland trips. There are many benefits to renting places like that....use of a kitchen for meals, laundry facilities, and like you said extra space to spread out! The cost can be steep but we end up saving in the end as we eat breakfast there, pack in our lunches, and have dinner back in the house. (we're a large travelling group.....11 total!)
The first time we rented a house was near where you are looking. We were off Cerritos Ave, down a little way and off Bayless St. We did walk the first day we were there and yes it is doable. However......its not a straight shot to get onto Disney property. There is a long wall along S Walnut St next to the Disneyland Hotel and you have to go all the way around it to get onto the property. (coming from Cerritos, we went to the left to get around the wall). Once you are around the wall, you will walk thru parking for the DL Hotel, then the hotel, then DTD, and then you will get to the security checkpoint. If I remember correctly, it took us about 25 mins to walk?? The houses where we were seemed like an older well-kept neighborhood, but there were some areas that seemed slightly run down. We didn't see any outright crime or felt unsafe, but I just remember feeling more aware of our surroundings as we walked. We did not do the walk at night however, just during daylight hours.
After a full day in the parks, the walk home was painful!! So for the remainder of our trip, we drove and parked in the parking garage.
Generally, we have had good experiences renting down there. One place had minor issues, like nothing to use for baking in the kitchen (like corning ware or cookie sheets) but the owner bought stuff for us while we were there.
Hope this helps!