Can I add support material?

it should not do that did you actually have support turned on when you sliced it or is what saw simply trying to print an actual part of the object that you only thought was support. I think this may be the case you can look in the gcode section of repetier host and if you select 3d view you can move the slider and see how your print would have printed layer by layer and see if it was actually support or part of the print

 

that doesn't look like it would actually need supports
I think supports start becoming almost a requirement at about 40-45 degrees
I think you are right on the edge but can't tell for sure from the image
In these prints the ONLY thing require supports was the chin area and in this desing he made the support himself so it could be quickly removed but the ears did not have any at all and they look like they are going out at lesser angle the yours print is

Let me know what you think

 

OK the print actually looks pretty good to be honest since you have a lot of question I still assume you are new and for being so this is actually pretty good

The bumps are completely normal it has to do with retraction settings, lift, speed, temp etc all combined at the same time and simply needs experience to tweak to get just right and then expect to do that for different materials all the time so get used to that part.But these are also more advanced issues so congrats on getting things this far.

The last picture is very tipical I get that on almost every print I make that is hollow it is still a retraction issue most likely there are things you can do to reduce them one setting in repetier is to check the avoid crossing perimeters box I think it is in the first category in the configuration setting s screen let me know if you have trouble finding it.

As far as your support question I am still confused by your description if you can try and get a picture of just that happening maybe even a little video.

I am not sure what you mean by the surface layers look terrible
it won't look smooth as glass unless you try it in ABS and then polish it but that is a WHOLE different ball game what is it that you do not like get a close up so we can see as well

the single line I see could be a fluke but if you said it was missing from the side then it may mean you are printing with your s height too high and the layers are not being set down and gently pushed together not sure though need more information.

There are thing I can look for but they are not evident in the pictures

also I am assuming this is PLA but don't know what layer heights you are using or what resolution you are trying to print at

I need to see a skirt or some brims
here is an example of what I would like to see it has lots of information in

 

No problem some of it ia learning curve and you are definitely on the right track that last image is probably the most horizontal of the four and the printer does what it can without supports if none are used and the resulting circle you see is a typical result of that attempt it may be that in this case a support may indeed be necessary to get that more intoa circular shape.

It can either be designed in like the yoda or stipulated in the software the problem with the software side of things is that it is an all or nothing affair so it could end up using a lot of filament and then have several areas that are not so smooth where supports were attached and on this one it would be a lot

as far a the first two images the print resolution you are using may have an affect as well I am not sure what resolution that is but the smaller the better but also the more time it takes to print I relegated myself to do most things in 200micron or .2 but somepeole want better result and go with .1 or even .075 or .050 but not sure how much success they have had with that

 

I just thought of something that could cause that support to mysteriously begin in mid air actually the only idea I have had about it and that is the drawing itself contains a small error that slicer interprets as needing to print something there. There is a program called netfabb it is free and I use it now on almost everything I print and it has teh ability to fix small little errors that you sometimes can not even see and the drawings afterwards have always come out better when using it

You basically load the stl file hit a small red cross looking symnbol choose the standard repair I think it is (I always do) begin the fix when it is done in a few seconds I export the srawing back to teh original stl file and I am good you may want to get netfabb and try it out on this object

it is actually called netfabb basic which is free it may solve that issue