Toddler discipline...

When I go home to Iowa I tend to have a lot of anxiety about how Micah will behave while there. I don't always know how he will react to new situations or if he will just have a bad day. I get so little time with my family that I really worry about what they will think...especially since he is the first baby around for the last 19 years.
I think my approach to parenting is patient and loving and my discipline is firm and consistent. I'm not afraid to give a controlled spank (I do not beat my child in any way) and then let him know I still love him. While I think I am consistent he definitely hasn't consistently shown good behavior...it's like a broken math equation to me....consistently discipline should equal consistent good behavior because of known consequences. This does NOT happen though. He is constantly testing his boundaries and asserting his (strong) will. He whimpers sometimes, he fusses, he is not always a gem when I put him down for a nap or bed. He can honestly REALLY test my patience and be naughty and leave me frazzled...he's definitely not perfect!
I am generally around a side of our family here in Ohio and I think they definitely tend toward a very loving patient parenting style. While I was at home in Iowa I realized a huge contrast in parenting philosophy from a ***couple*** (not nearly all) of my family members. I kept hearing comments about what a handful he was....said in a way that did not seem to understand that he is a toddler with energy but insinuated that he was just a naughty boy. (during a time I thought he was being good!) One of my family members even took it upon his/her self to spank him when he/she thought he was being bad...which definitely rubbed me the wrong way since Micah doesn't even know this person from any other person on the street.
Anyways I really was faced with a very harsh seeming form of discipline (to me). Part of me thinks most of my family just hasn't been around small children for ages so don't realize how almost 2-year olds act and they are just grumpy people who don't appreciate the creativity of toddlers and are dying to wield their authority on others. The other part of me questions how I parent and wonders if by now Micah should be really good all the time because he really knows the awful consequences of being naughty like being spanked constantly. Maybe I'm creating 'that kid' for the kindergarten teacher that makes her room look like a tornado blew through. Maybe he will grow up with no boundaries and turn into an awful rebel.
My gut says he is a sweet little guy who is practicing being independent and who often gets frustrated because he is not very good at communicating what he wants/needs. I think he struggles a little in some new situations like taking naps at different homes and he gets bored when he is in the house a lot with nothing to do. And sometimes he IS just strong-willed and naughty.
I really want to respect how sine of my family deals with things and maybe I'm looking on a few people too harshly because I felt like such a bad parent around them (by not wielding enough authority and spanking enough/quickly enough, using anger..etc.)
Anyways, parenting is HARD and I know that I am a HUGE WORK IN PROGRESS!!! I have no doubt that I often don't have a clue. All this questioning has led me to think A LOT about God and how I really need to do my best with Micah and trust in him that he will lead both me and Micah the way we should be.