Sounds like your little guy has a great imagination!
Experts and those of us who have worked with young ones for a long time know that the very *best* toys are those which offer open-ended imaginary play. Boxes, containers, blocks, bags, those cardboard oatmeal tubes, squares of fabric.... simple items can be used in multiple ways.
When we think of kids using things inappropriately as a 'red flag', I think most of us would be looking for destructive behaviors, like throwing blocks at others, ripping books (little kids *do* do this by the way, which is why we offer board books, fabric books, lots of supervision and also offer appropriate items to explore 'tearing', like paper bags or recycled paper). Red flags would be mean, brutal treatment of baby dolls or stuffed animals -- that said, kids will often color on these items or give them 'haircuts', etc. Crashing cars and trains is also normal. I should also add that a child's concerning behaviors would not be isolated to how they play with their toys, it would also be apparent in their outward treatment of parents, siblings, playmates and family pets. *Those* are the red flags to be concerned about.
Clever children can make anything 'become' anything else. Sounds like you have a very engaged little guy. Personally, I think the kids who can be more versatile with toys are usually the ones who are more fun to be around. :)
Enjoy your little guy and don't worry so much.
ETA: must respectfully add a caution to the warning about 'lining up' toys-- I have seen this with a handful of children, all of them were pretty bright. If the toys are being lined up as the activity in and of itself, that's really okay. What I did notice about those children is that they do have a bit more of a rigid personality in liking things to be done a certain 'right' way, which comes with its own challenges. However, it isn't always indicative of a developmental delay-- all information about a child should be taken in context of the bigger picture of their lives. The other information about lining up PLUS the licking/sensory exploration-- I agree with JB wholeheartedly. The only reason I mention this is because some parents really get upset when they see their kid 'just lining up' the toys; I honestly believe this has to do with developing abilities of sorting, categorizing, clustering like objects, and making things 'orderly'. I've seen a child line up six pillows, then place one baby on each pillow, then cover each baby with a blanket. She's now a college sophomore on a full-ride scholarship majoring in microbiology, *super bright* lovely young lady. Just wanted to put that in there so parents don't worry too much!