Can you meditate too much as part of a daily routine?

If meditation is interfering with your life and relationships, then you are meditating too much. Follow the Middle Way. If you do not have a life, or relationships, then why are you bothering?

My meditation teacher (authorized by my guru to teach it) said that it is how you are in life that shows your progress, not how you personally feel, and that other people will probably see changes in you before you see them.

I will answer your second question first, signs of too much meditation are that you TRULY feel bored or really sleepy. In that case stop meditating. Like anything, meditation is a practice and practice doesn't make perfect. PERFECT practice makes perfect. So make sure you are curious enough about your own Self, self, and the Great Experiment of Buddhism. Otherwise you will end up wasting your time. You also have to draw a fine line between running off from meditation because you need to read more about it and running off because you're lazy or you just feel a little pain from your legs. If the latter, try harder. Challenge yourself sometimes!!

Too much meditation? If you look at the suttas, there are people who attained realization in seven days by practicing meditation day and night, inspired by the Buddha's words.

These are people that had the proper teachings and thus motivated practice. For someone who is a beginner and who doesn't understand the entire picture, it is not good to meditate too much because then the person will become repulsed and extremely outcome-oriented. For beginners, it is important to get used to meditation first... but just know that you won't get enlightened or attain mastery of your state of mind, body, heart (and even reality itself) without staying in meditation longer and longer periods of time.

On the other hand, there are some Buddhist professors who should be meditating all day! (Because they have enough knowledge to accomplish Enlightenment. They've been studying for decades and not even practicing but just arbitrating smaller irrelevant concepts.)

Please see the free book by Daniel Ingram's "Mastering the Core Teachings of the Buddha" chapter about meditation scheduling and when to do it and how long.

According to stackexchange guidelines I should regurgitate the info here but I decide not to because the book will always be available and is free. Read the chapter I mentioned and then read the whole book. Also I didn't regurgitate because my response should very fully gives you enough hints.

Also here is an excerpt from one the best books I have ever read about Buddhism: (the advice offers a different perspective from above... equally valid)

"The main rule is to be at ease and thoroughly relaxed in muscles, nerves, and brain. Noises and bright light may create tension, and darkness may cause sleepiness. It is better to meditate often for a shorter time than for a long time but infrequently. To make real progress, meditation should become a vital part of one’s daily life. Meditation masters recommended to their students: “Do it with an aspiration so strong that it will be the cause of fulfilling your provisional and final aims. Meditate in this way during four sessions: predawn, morning, afternoon, and at nightfall. Furthermore, if at first you meditate for a long time, you will be readily susceptible to laxity and excitement. If this becomes your habit, it will then be difficult to correct your awareness. Meditate in many short sessions. If you end your session while still wanting to meditate, you will be eager to reenter each future session." --Mind Experiment pg. 201

You practice should be continuous. Therefore there is only the risk of practising too little. But there is the risk of too much effort. This is generally chasing after results, exerting too much control like keeping you mind on the meditation object.